Pub Date : 2025-01-21DOI: 10.1016/j.jajp.2025.100284
Wilfried Pacquentin , Pierre Wident , Jérôme Varlet , Thomas Cailloux , Hicham Maskrot
Additive manufacturing (AM) is a proven time- and cost-effective method for repairing parts locally damaged after e.g. repetitive friction wear or corrosion. Repairing a hardfacing coating using AM technologies presents however several simultaneous challenges arising from the complex geometry and a high probability of crack formation due to process-induced stress. We address the repair of a cobalt-based Stellite™ 6 hardfacing coating on an AISI 316L substrate performed using Laser Powder Directed Energy Deposition (LP-DED) and investigate the influence of key process features and parameters. We describe our process which successfully prevents crack formation both during and after the repair, highlighting the design of the preliminary part machining phase, induction heating of an extended part volume during the laser repair phase and the optimal scanning strategy. Local characterization using non-destructive testing, Vickers hardness measurements and microstructural examinations by scanning electron microscopy (SEM) show an excellent metallurgical quality of the repair and its interface with the original part. In addition, we introduce an innovative process qualification test assessing the repair quality and innocuity, which is based on the global response to induced cracks and probes the absence of crack attraction by the repair (ACAR1). Here this ACAR test reveals a slight difference in mechanical behavior between the repair and the original coating which motivates further work to eventually make the repair imperceptible.
{"title":"Temperature influence on the repair of a hardfacing coating using laser metal deposition and assessment of the repair innocuity","authors":"Wilfried Pacquentin , Pierre Wident , Jérôme Varlet , Thomas Cailloux , Hicham Maskrot","doi":"10.1016/j.jajp.2025.100284","DOIUrl":"10.1016/j.jajp.2025.100284","url":null,"abstract":"<div><div>Additive manufacturing (AM) is a proven time- and cost-effective method for repairing parts locally damaged after e.g. repetitive friction wear or corrosion. Repairing a hardfacing coating using AM technologies presents however several simultaneous challenges arising from the complex geometry and a high probability of crack formation due to process-induced stress. We address the repair of a cobalt-based Stellite™ 6 hardfacing coating on an AISI 316L substrate performed using Laser Powder Directed Energy Deposition (LP-DED) and investigate the influence of key process features and parameters. We describe our process which successfully prevents crack formation both during and after the repair, highlighting the design of the preliminary part machining phase, induction heating of an extended part volume during the laser repair phase and the optimal scanning strategy. Local characterization using non-destructive testing, Vickers hardness measurements and microstructural examinations by scanning electron microscopy (SEM) show an excellent metallurgical quality of the repair and its interface with the original part. In addition, we introduce an innovative process qualification test assessing the repair quality and innocuity, which is based on the global response to induced cracks and probes the absence of crack attraction by the repair (ACAR<span><span><sup>1</sup></span></span>). Here this ACAR test reveals a slight difference in mechanical behavior between the repair and the original coating which motivates further work to eventually make the repair imperceptible.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100284"},"PeriodicalIF":3.8,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.1016/j.jajp.2025.100287
Rupendra Singh Tanwar, Suyog Jhavar
In this work, bimetallic structures of two austenitic steels (SS316L and SS309) were fabricated using wire arc Direct Energy Deposition (DED). The fabrication process involved in the strategy of SS316L-SS309-SS316L on an SS316L substrate sequentially. Each material deposited 10 layers to one over another and forming two interfaces. Subsequently, the microstructure and mechanical properties, were evaluated in the deposited materials and at their interface. The microstructure predominantly consisted of the austenitic (γ) phase with a minimal amount of δ-ferrite phases in both stainless steels. The elemental distribution confirmed through EDS and verified by the Schaeffler diagram. SS309 exhibited a higher δ ferrite content compared to SS316L, and the interfaces showed a δ-ferrite content between the two base metals, the δ-ferrite mitigate the issue of hot cracking which occurred generally in the austenitic steels. The hardness ranged from 206 to 289 Vickers hardness (HV), with a considerable increase at the interface due to concentration of δ ferrite. The yield and ultimate tensile strengths were higher in the bimetallic samples tested in the build direction compared to the deposition direction with minimal variation indicating low anisotropy in mechanical properties. Tensile fracture results showed dimples, deep dimples, and microcracks, with failures occurring on the SS316L side. These findings demonstrate the effectiveness of the wire arc DED process in fabricating of bimetallic structure of SS316L-SS309 with improved strength.
{"title":"Investigation of microstructure and mechanical properties of austenitic steel bimetallic structures fabricated using wire arc direct energy deposition for remanufacturing applications","authors":"Rupendra Singh Tanwar, Suyog Jhavar","doi":"10.1016/j.jajp.2025.100287","DOIUrl":"10.1016/j.jajp.2025.100287","url":null,"abstract":"<div><div>In this work, bimetallic structures of two austenitic steels (SS316L and SS309) were fabricated using wire arc Direct Energy Deposition (DED). The fabrication process involved in the strategy of SS316L-SS309-SS316L on an SS316L substrate sequentially. Each material deposited 10 layers to one over another and forming two interfaces. Subsequently, the microstructure and mechanical properties, were evaluated in the deposited materials and at their interface. The microstructure predominantly consisted of the austenitic (γ) phase with a minimal amount of δ-ferrite phases in both stainless steels. The elemental distribution confirmed through EDS and verified by the Schaeffler diagram. SS309 exhibited a higher δ ferrite content compared to SS316L, and the interfaces showed a δ-ferrite content between the two base metals, the δ-ferrite mitigate the issue of hot cracking which occurred generally in the austenitic steels. The hardness ranged from 206 to 289 Vickers hardness (HV), with a considerable increase at the interface due to concentration of δ ferrite. The yield and ultimate tensile strengths were higher in the bimetallic samples tested in the build direction compared to the deposition direction with minimal variation indicating low anisotropy in mechanical properties. Tensile fracture results showed dimples, deep dimples, and microcracks, with failures occurring on the SS316L side. These findings demonstrate the effectiveness of the wire arc DED process in fabricating of bimetallic structure of SS316L-SS309 with improved strength.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100287"},"PeriodicalIF":3.8,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study is focused on improving the joint strength of AA7075-T6 specimens with aluminium cladding (alclad) joined through the refill friction stir spot welding (RFSSW) process. The bonding ligament weakens the RFSSW joint because the alclad layer is trapped between the specimens. This layer hinders material mixing during welding and creates a weak interface prone to crack initiation and propagation during external loading, affecting joint integrity. To overcome this problem, a novel tool sequencing variant of RFSSW, the pin plunging reinforced RFSSW (PPRSP-RFSSW), is proposed. A smoothed-particle hydrodynamics (SPH) formulation-based 3D thermo-mechanical model is developed to study the thermo-mechanical and material flow properties as it is possible to trace the field variables explicitly; it can manage significant material/elemental deformations and capture material mixing dynamically. The PPRSP-RFSSW is numerically analyzed and compared to existing sleeve plunging RFSSW (SP-RFSSW). The numerical model's accuracy was tested by comparing temperatures to experimental temperature data in published papers, and the results corresponded well. Comparisons are made between the SP-RFSSW and PPRSP-RFSSW concerning their heat distribution, plasticization, and material flow. Enhanced material mixing and plasticization were observed through PPRSP-RFSSW, and this tool sequencing is recommended for joining alclad AA7075-T6 specimens.
{"title":"Thermo-mechanical and material flow characteristics of tool sequencing dynamics in refill FSSW of thin alclad AA7075-T6 sheets: Numerical analysis using meshless smoothed-particle hydrodynamics method","authors":"Venkata Somi Reddy Janga, Mokhtar Awang, Nabihah Sallih, Tamiru Alemu Lemma","doi":"10.1016/j.jajp.2025.100285","DOIUrl":"10.1016/j.jajp.2025.100285","url":null,"abstract":"<div><div>This study is focused on improving the joint strength of AA7075-T6 specimens with aluminium cladding (alclad) joined through the refill friction stir spot welding (RFSSW) process. The bonding ligament weakens the RFSSW joint because the alclad layer is trapped between the specimens. This layer hinders material mixing during welding and creates a weak interface prone to crack initiation and propagation during external loading, affecting joint integrity. To overcome this problem, a novel tool sequencing variant of RFSSW, the pin plunging reinforced RFSSW (PPRSP-RFSSW), is proposed. A smoothed-particle hydrodynamics (SPH) formulation-based 3D thermo-mechanical model is developed to study the thermo-mechanical and material flow properties as it is possible to trace the field variables explicitly; it can manage significant material/elemental deformations and capture material mixing dynamically. The PPRSP-RFSSW is numerically analyzed and compared to existing sleeve plunging RFSSW (SP-RFSSW). The numerical model's accuracy was tested by comparing temperatures to experimental temperature data in published papers, and the results corresponded well. Comparisons are made between the SP-RFSSW and PPRSP-RFSSW concerning their heat distribution, plasticization, and material flow. Enhanced material mixing and plasticization were observed through PPRSP-RFSSW, and this tool sequencing is recommended for joining alclad AA7075-T6 specimens.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100285"},"PeriodicalIF":3.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-16DOI: 10.1016/j.jajp.2025.100286
R.F. Rezende , A.R. Arias , E.J. Lima II , F.G.F. Coelho
This study aimed to introduce pulsed gas metal arc welding (GMAW)-based wire arc additive manufacturing (WAAM) for the deposition of 308 L stainless steel. Then, the influence of the different droplet detachment modes on the geometric characteristics and mechanical properties of the deposited metal were analyzed. The detachment modes of one drop per multiple pulses (ODMP), one drop per pulse (ODPP), and multiple drops per pulse (MDPP) were analyzed. The experiments were performed by depositing preforms using 308 L stainless steel wire with a diameter of 1.0 mm on a 316 L stainless steel substrate. Characterization of the droplet detachment modes was performed using a high-speed camera and data acquisition system. Geometric analysis of the preforms was performed by photogrammetry. A greater heat input was observed in the ODMP mode. The MDPP and ODPP modes produced thinner preforms with a better surface finish. In addition, the MDPP mode generated better results in the manufactured preforms, with lower hardness and higher tensile strength. However, the ODMP mode led to relatively poorer results, with wider walls, greater surface waviness, and lower tensile strength. The results of this research are expected to provide technical and scientific support for the development of additive manufacturing by arc deposition, especially for stainless steel applications.
{"title":"Pulsed GMAW-based WAAM–Influence of droplet detachment mode on the geometry and mechanical properties of 308 L stainless steel","authors":"R.F. Rezende , A.R. Arias , E.J. Lima II , F.G.F. Coelho","doi":"10.1016/j.jajp.2025.100286","DOIUrl":"10.1016/j.jajp.2025.100286","url":null,"abstract":"<div><div>This study aimed to introduce pulsed gas metal arc welding (GMAW)-based wire arc additive manufacturing (WAAM) for the deposition of 308 L stainless steel. Then, the influence of the different droplet detachment modes on the geometric characteristics and mechanical properties of the deposited metal were analyzed. The detachment modes of one drop per multiple pulses (ODMP), one drop per pulse (ODPP), and multiple drops per pulse (MDPP) were analyzed. The experiments were performed by depositing preforms using 308 L stainless steel wire with a diameter of 1.0 mm on a 316 L stainless steel substrate. Characterization of the droplet detachment modes was performed using a high-speed camera and data acquisition system. Geometric analysis of the preforms was performed by photogrammetry. A greater heat input was observed in the ODMP mode. The MDPP and ODPP modes produced thinner preforms with a better surface finish. In addition, the MDPP mode generated better results in the manufactured preforms, with lower hardness and higher tensile strength. However, the ODMP mode led to relatively poorer results, with wider walls, greater surface waviness, and lower tensile strength. The results of this research are expected to provide technical and scientific support for the development of additive manufacturing by arc deposition, especially for stainless steel applications.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100286"},"PeriodicalIF":3.8,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-12DOI: 10.1016/j.jajp.2025.100283
Ning Zhu , Trevor Hickok , Kirk A. Fraser , Dunji Yu , Yan Chen , Ke An , Luke N. Brewer , Paul G. Allison , J. Brian Jordon
This work examines the residual stress in high-strength aluminum alloy repaired by lubricant-free additive friction stir deposition (AFSD) using the same aluminum alloy feedstock. Specifically, a milled groove in an AA7075-T651 substrate was repaired using the twin rod additive friction stir deposition (TR-AFSD) without using any graphite lubricant on the feedstock materials, which is required for conventional square feedstock AFSD. Residual stress distribution in the repaired substrate at different depths was quantified via neutron diffraction, where the distribution of longitudinal residual stress in the TR-AFSD repair was found comparable to materials subjected to other friction-based processes, with an M-shaped or bell-shaped distribution. The tensile longitudinal residual stress, with a peak of 171.3 MPa, spanned the center region around 36 mm, while compressive longitudinal residual stresses, ranging between -112.9 MPa and -12.3 MPa, were balanced outside the center at both the advancing side and retreating sides. The transverse and normal residual stresses were consistent across the repair, with smaller magnitudes between -52 MPa and 68.3 MPa. The non-destructive and high penetration depth nature of the neutron diffraction method enabled the calculation of von Mises stress by interpreting the three measured orthogonal residual stresses as the principal stresses. By normalizing the calculated von Mises stress to the microhardness, this quantified ratio indicates the influence of the embedded residual stresses relative to the material's strength. The higher normalized ratio observed at a deeper depth closer to the bottom of the repair, suggests that the magnitude of residual stresses is closer to the material's strength, indicating a higher potential for residual stress-induced failure at this location. We also calibrated the state-of-the-art smooth particle hydrodynamic (SPH) TR-AFSD process model to predict the von Mises stress distribution in the TR-AFSD AA7075 repair. The experimentally measured residual stress, coupled with the SPH simulation, could further help the research community to minimize the tensile region and alleviate substrate distortion in materials subjected to friction-based processes.
{"title":"Neutron diffraction analysis of residual stress distribution in the lubricant-free TR-AFSD AA7075 repair coupled with SPH simulations","authors":"Ning Zhu , Trevor Hickok , Kirk A. Fraser , Dunji Yu , Yan Chen , Ke An , Luke N. Brewer , Paul G. Allison , J. Brian Jordon","doi":"10.1016/j.jajp.2025.100283","DOIUrl":"10.1016/j.jajp.2025.100283","url":null,"abstract":"<div><div>This work examines the residual stress in high-strength aluminum alloy repaired by lubricant-free additive friction stir deposition (AFSD) using the same aluminum alloy feedstock. Specifically, a milled groove in an AA7075-T651 substrate was repaired using the twin rod additive friction stir deposition (TR-AFSD) without using any graphite lubricant on the feedstock materials, which is required for conventional square feedstock AFSD. Residual stress distribution in the repaired substrate at different depths was quantified via neutron diffraction, where the distribution of longitudinal residual stress in the TR-AFSD repair was found comparable to materials subjected to other friction-based processes, with an M-shaped or bell-shaped distribution. The tensile longitudinal residual stress, with a peak of 171.3 MPa, spanned the center region around 36 mm, while compressive longitudinal residual stresses, ranging between -112.9 MPa and -12.3 MPa, were balanced outside the center at both the advancing side and retreating sides. The transverse and normal residual stresses were consistent across the repair, with smaller magnitudes between -52 MPa and 68.3 MPa. The non-destructive and high penetration depth nature of the neutron diffraction method enabled the calculation of von Mises stress by interpreting the three measured orthogonal residual stresses as the principal stresses. By normalizing the calculated von Mises stress to the microhardness, this quantified ratio indicates the influence of the embedded residual stresses relative to the material's strength. The higher normalized ratio observed at a deeper depth closer to the bottom of the repair, suggests that the magnitude of residual stresses is closer to the material's strength, indicating a higher potential for residual stress-induced failure at this location. We also calibrated the state-of-the-art smooth particle hydrodynamic (SPH) TR-AFSD process model to predict the von Mises stress distribution in the TR-AFSD AA7075 repair. The experimentally measured residual stress, coupled with the SPH simulation, could further help the research community to minimize the tensile region and alleviate substrate distortion in materials subjected to friction-based processes.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100283"},"PeriodicalIF":3.8,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-10DOI: 10.1016/j.jajp.2025.100282
Hamed Razavi , Hamid Reza Masoumi
This study investigates the impact of ultrasonic vibrations on the press-fitting process, aiming to reduce the maximum press-fit force required in mechanical assemblies. Press-fitting involves inserting a pin into a bushing of a slightly smaller diameter, leading to high press-fit forces, which is crucial in the analysis and performance assessment of the process. The research investigates the effects of assembly speed and ultrasonic vibration power on the reduction of press-fit force. Through a series of 15 distinct experiments employing both conventional press-fitting (CPF) and ultrasonic-assisted press-fitting (UAPF), it was found that increasing the power of ultrasonic vibrations leads to a significant decrease in the maximum press-fit force, whereas reducing the assembly speed has a minor effect. The maximum press-fit force is reduced by over 80 % when utilizing maximum vibration power. The findings indicate that the UAPF method is a promising technique to reduce the maximum press-fit force, thus improving the feasibility of the press-fitting process. This research has significant implications for the manufacturing industry, enabling the assembly of sensitive parts without excessive force and improving the overall assembly performance.
{"title":"Ultrasonic-assisted press-fitting: A superior method for reducing press-fit force compared to conventional press-fitting","authors":"Hamed Razavi , Hamid Reza Masoumi","doi":"10.1016/j.jajp.2025.100282","DOIUrl":"10.1016/j.jajp.2025.100282","url":null,"abstract":"<div><div>This study investigates the impact of ultrasonic vibrations on the press-fitting process, aiming to reduce the maximum press-fit force required in mechanical assemblies. Press-fitting involves inserting a pin into a bushing of a slightly smaller diameter, leading to high press-fit forces, which is crucial in the analysis and performance assessment of the process. The research investigates the effects of assembly speed and ultrasonic vibration power on the reduction of press-fit force. Through a series of 15 distinct experiments employing both conventional press-fitting (CPF) and ultrasonic-assisted press-fitting (UAPF), it was found that increasing the power of ultrasonic vibrations leads to a significant decrease in the maximum press-fit force, whereas reducing the assembly speed has a minor effect. The maximum press-fit force is reduced by over 80 % when utilizing maximum vibration power. The findings indicate that the UAPF method is a promising technique to reduce the maximum press-fit force, thus improving the feasibility of the press-fitting process. This research has significant implications for the manufacturing industry, enabling the assembly of sensitive parts without excessive force and improving the overall assembly performance.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100282"},"PeriodicalIF":3.8,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An innovative anti-loosening bolt with a double-thread mechanism (denoted as DTB-IIC) consisting of coaxial single and multiple coarse threads was previously devised and its structure and performance were optimized. The results of a previous study showed that increasing the bottom rise ratio , which is the ratio of the bottom rise for the multi-thread groove to the thread height, to 70 % significantly improved the formability during the thread-rolling process, but clearly reduced the loosening resistance. In the present study, an attempt was made to address this problem in a simple manner by inserting a left-handed spring washer (SW) between the inner multi-thread nut and the outer single-thread nut. The value of was set to 50 %, 60 %, or 70 %. Comparative Junker vibration loosening tests based on the ISO 16,130 standard were conducted and the change in the residual ratio for the axial load, , was evaluated. Without the SW, the final () for was above 90 %, while for and , it was approximately 73 % and 64 %, respectively. Attachment of the SW caused an increase in for all values, with a greater increase for larger , reaching 82 % for = 60 % and 75 % for = 70 %, respectively. It was found that the contact force between the nuts is an indicator for determining the degree of locking between the DTB-IIC and the nut. The initial loosening process was simulated using a three-dimensional finite element method model, and the curves obtained in the analysis agreed well with the experimental results by setting the gap between the inner multi-thread nut and the DTB-IIC bolt in the range 0.125–0.15 mm. The simulation results indicated that there were clear differences in mating state between the outer nut and the DTB-IIC depending on the value, and the use of a SW achieved a more robust locking state when was 50 %.
{"title":"Improvement of anti-loosening resistance of locking bolts based on single-coarse-thread/multiple-coarse-thread mechanism by using spring washer between nuts","authors":"Shuichi Amano , Toshinaka Shinbutsu , Yuki Okimoto , Teruie Takemasu , Toshihiko Kuwabara","doi":"10.1016/j.jajp.2025.100280","DOIUrl":"10.1016/j.jajp.2025.100280","url":null,"abstract":"<div><div>An innovative anti-loosening bolt with a double-thread mechanism (denoted as DTB-IIC) consisting of coaxial single and multiple coarse threads was previously devised and its structure and performance were optimized. The results of a previous study showed that increasing the bottom rise ratio <span><math><mi>β</mi></math></span>, which is the ratio of the bottom rise for the multi-thread groove to the thread height, to 70 % significantly improved the formability during the thread-rolling process, but clearly reduced the loosening resistance. In the present study, an attempt was made to address this problem in a simple manner by inserting a left-handed spring washer (SW) between the inner multi-thread nut and the outer single-thread nut. The value of <span><math><mi>β</mi></math></span> was set to 50 %, 60 %, or 70 %. Comparative Junker vibration loosening tests based on the ISO 16,130 standard were conducted and the change in the residual ratio for the axial load, <span><math><mi>κ</mi></math></span>, was evaluated. Without the SW, the final <span><math><mi>κ</mi></math></span> (<span><math><msub><mi>κ</mi><mi>f</mi></msub></math></span>) for <span><math><mrow><mi>β</mi><mo>=</mo><mn>50</mn><mspace></mspace><mo>%</mo></mrow></math></span> was above 90 %, while <span><math><msub><mi>κ</mi><mi>f</mi></msub></math></span> for <span><math><mrow><mi>β</mi><mo>=</mo><mn>60</mn><mspace></mspace><mo>%</mo></mrow></math></span> and <span><math><mrow><mi>β</mi><mo>=</mo><mn>70</mn><mspace></mspace><mo>%</mo></mrow></math></span>, it was approximately 73 % and 64 %, respectively. Attachment of the SW caused an increase in <span><math><msub><mi>κ</mi><mi>f</mi></msub></math></span> for all <span><math><mi>β</mi></math></span> values, with a greater increase for larger <span><math><mi>β</mi></math></span>, reaching 82 % for <span><math><mi>β</mi></math></span> = 60 % and 75 % for <span><math><mi>β</mi></math></span> = 70 %, respectively. It was found that the contact force between the nuts is an indicator for determining the degree of locking between the DTB-IIC and the nut. The initial loosening process was simulated using a three-dimensional finite element method model, and the <span><math><mi>κ</mi></math></span> curves obtained in the analysis agreed well with the experimental results by setting the gap <span><math><mi>δ</mi></math></span> between the inner multi-thread nut and the DTB-IIC bolt in the range 0.125–0.15 mm. The simulation results indicated that there were clear differences in mating state between the outer nut and the DTB-IIC depending on the <span><math><mi>β</mi></math></span> value, and the use of a SW achieved a more robust locking state when <span><math><mi>β</mi></math></span> was 50 %.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100280"},"PeriodicalIF":3.8,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Continuous drive friction welding (CDFW) is a highly efficient technique for fabricating large Polyether-ether-ketone (PEEK) components. However, the bending strength of welded specimens is often constrained by the formation of pores at the weld interface. Addressing this limitation, this study aims to enhance the bending strength of PEEK polymer cylinders by applying ultrasound-assisted continuous drive friction welding (UACDFW). To further improve joint performance, a novel post-compression technique is introduced and used after the welding process to increase the weld-bonded area. Additionally, image processing software is employed to evaluate and analyze the weld-bonded area ratio, comprehensively assessing the interfacial characteristics. Optimizing CDFW parameters increased the bending strength of the welded components from 201.6 MPa to 380.8 MPa and the joint area ratio from 77.54 % to 99.99 %. The optimized parameters include a rotational speed of 4000 rpm, a preheating time of 5 s, and a post-compression feed rate of 3.2 mm/s. The results demonstrate the potential of UACDFW and post-compression techniques as effective solutions for improving the mechanical performance and reliability of PEEK components in high-performance applications.
{"title":"Enhancing the weld quality of polyetheretherketone polymer cylinders using reducing pores in the weld interface","authors":"Chil-Chyuan Kuo , Xiao-Ze Xie , Chong-Xu Liao , Wen-Bin Huang , Yu-Jie Chen , Armaan Farooqui , Song-Hua Huang , Shih-Feng Tseng","doi":"10.1016/j.jajp.2025.100281","DOIUrl":"10.1016/j.jajp.2025.100281","url":null,"abstract":"<div><div>Continuous drive friction welding (CDFW) is a highly efficient technique for fabricating large Polyether-ether-ketone (PEEK) components. However, the bending strength of welded specimens is often constrained by the formation of pores at the weld interface. Addressing this limitation, this study aims to enhance the bending strength of PEEK polymer cylinders by applying ultrasound-assisted continuous drive friction welding (UACDFW). To further improve joint performance, a novel post-compression technique is introduced and used after the welding process to increase the weld-bonded area. Additionally, image processing software is employed to evaluate and analyze the weld-bonded area ratio, comprehensively assessing the interfacial characteristics. Optimizing CDFW parameters increased the bending strength of the welded components from 201.6 MPa to 380.8 MPa and the joint area ratio from 77.54 % to 99.99 %. The optimized parameters include a rotational speed of 4000 rpm, a preheating time of 5 s, and a post-compression feed rate of 3.2 mm/s. The results demonstrate the potential of UACDFW and post-compression techniques as effective solutions for improving the mechanical performance and reliability of PEEK components in high-performance applications.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100281"},"PeriodicalIF":3.8,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-02DOI: 10.1016/j.jajp.2024.100278
Nagaraju Doredla, Senthil Kumar N
Ferrite-Pearlite (α-P) steels like E350 steel were extensively used in pre-engineered structures like industrial warehouses, bridges, etc., owing to their special ductility property. Submerged arc welding is highly efficient in welding long-span prefabricated structures. In this paper, weld overlay and butt weld experimental investigations were performed to optimise the welding process by understanding the influence of heat input on residual stress generation, weld efficiency, microstructural and mechanical characteristics of the weld joint to match the filler wire with the base material characteristics. Trail runs were conducted using the Taguchi design optimisation approach. Taguchi method is useful to standardise and simplify the use of design of experiments. The weld quality was evaluated using non-destructive evaluations. Residual stress was tensile near the weld and transitioned to compressive further from the root. The intensity of residual stress decreased gradually with an increase in transverse distance from the weld root. Acicular ferrite, polygonal ferrite, and traces of lath bainite microstructure were observed in the weld zone. The weld microstructure became coarser toward the melting boundary of the welded joint with an increase in heat input greater than 1.09 kJ/mm. A notable decrease in weld brittleness was observed with an increase in heat input from 1.09–1.37 kJ/mm, and the fracture initiated away from the weld with ductile and quasi-ductile cleavages. The overall microstructure and mechanical characteristics of the welded joint were improved at a controlled heat input of 1.09–1.37 kJ/mm.
{"title":"Determination of heat input impact on residual stress, microstructure and mechanical characteristics of welded ferrite-pearlite (α-P) steel joints by using taguchi optimization approach","authors":"Nagaraju Doredla, Senthil Kumar N","doi":"10.1016/j.jajp.2024.100278","DOIUrl":"10.1016/j.jajp.2024.100278","url":null,"abstract":"<div><div>Ferrite-Pearlite (α-P) steels like E350 steel were extensively used in pre-engineered structures like industrial warehouses, bridges, etc., owing to their special ductility property. Submerged arc welding is highly efficient in welding long-span prefabricated structures. In this paper, weld overlay and butt weld experimental investigations were performed to optimise the welding process by understanding the influence of heat input on residual stress generation, weld efficiency, microstructural and mechanical characteristics of the weld joint to match the filler wire with the base material characteristics. Trail runs were conducted using the Taguchi design optimisation approach. Taguchi method is useful to standardise and simplify the use of design of experiments. The weld quality was evaluated using non-destructive evaluations. Residual stress was tensile near the weld and transitioned to compressive further from the root. The intensity of residual stress decreased gradually with an increase in transverse distance from the weld root. Acicular ferrite, polygonal ferrite, and traces of lath bainite microstructure were observed in the weld zone. The weld microstructure became coarser toward the melting boundary of the welded joint with an increase in heat input greater than 1.09 kJ/mm. A notable decrease in weld brittleness was observed with an increase in heat input from 1.09–1.37 kJ/mm, and the fracture initiated away from the weld with ductile and quasi-ductile cleavages. The overall microstructure and mechanical characteristics of the welded joint were improved at a controlled heat input of 1.09–1.37 kJ/mm.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100278"},"PeriodicalIF":3.8,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-30DOI: 10.1016/j.jajp.2024.100279
John Cance, Afsaneh Rabiei
Metal foams are notable for their impressive impact and thermal energy absorption capabilities primarily when compared to bulk metals. Composite metal foams (CMF) exemplify these properties through unchallenged structural uniformity, enhanced by an arrangement of similar prefabricated hollow metal spheres suspended within a metallic matrix. CMF's extraordinary physical, thermal, and mechanical properties make it a prime candidate for replacing bulk materials in various structural applications. However, the use of CMF in larger structures requires the implementation of joining methods. Solid-state joining processes are particularly well-suited for metal foams as they can form solid bonds between porous workpieces without distorting their cellular structures. Previous success was achieved in joining CMF panels up to 2.5 cm thick through induction welding, though localized heating through induced Eddy currents could not fully permeate thicker samples. This limitation has caused a shift in focus to diffusion bonding of CMF panels thicker than 2.5 cm. This process utilizes a vacuum furnace, combining heat with intense pressure to facilitate atomic diffusion between workpieces. This study evaluates the suitability of diffusion bonding in joining CMF panels through a combination of uniaxial tensile tests and scanning electron microscopy (SEM) observations. Tensile testing indicated bond strength to be largely affected by sample density, and in turn, consistency of the steel powder used in CMF production. Overall, diffusion bonding of CMF was successful from thicknesses below 2.5 cm up to 5 cm, with material density and surface preparation being the apparent driving factors to successful bonding.
{"title":"Study on diffusion bonding of composite metal foams","authors":"John Cance, Afsaneh Rabiei","doi":"10.1016/j.jajp.2024.100279","DOIUrl":"10.1016/j.jajp.2024.100279","url":null,"abstract":"<div><div>Metal foams are notable for their impressive impact and thermal energy absorption capabilities primarily when compared to bulk metals. Composite metal foams (CMF) exemplify these properties through unchallenged structural uniformity, enhanced by an arrangement of similar prefabricated hollow metal spheres suspended within a metallic matrix. CMF's extraordinary physical, thermal, and mechanical properties make it a prime candidate for replacing bulk materials in various structural applications. However, the use of CMF in larger structures requires the implementation of joining methods. Solid-state joining processes are particularly well-suited for metal foams as they can form solid bonds between porous workpieces without distorting their cellular structures. Previous success was achieved in joining CMF panels up to <em>2.5</em> cm thick through induction welding, though localized heating through induced Eddy currents could not fully permeate thicker samples. This limitation has caused a shift in focus to diffusion bonding of CMF panels thicker than <em>2.5</em> cm. This process utilizes a vacuum furnace, combining heat with intense pressure to facilitate atomic diffusion between workpieces. This study evaluates the suitability of diffusion bonding in joining CMF panels through a combination of uniaxial tensile tests and scanning electron microscopy (SEM) observations. Tensile testing indicated bond strength to be largely affected by sample density, and in turn, consistency of the steel powder used in CMF production. Overall, diffusion bonding of CMF was successful from thicknesses below <em>2.5</em> cm up to <em>5</em> cm, with material density and surface preparation being the apparent driving factors to successful bonding.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100279"},"PeriodicalIF":3.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143133040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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