Mohsin Khan K, T. B. Rao, R. Mohammed, Manjunath B N, K. Abhinav, Vinod A R
In this investigation, IN625 alloy samples were processed by directed energy deposition (DED) under various metal deposition strategies such as substrate preheating, inter-layer dwell, and with combined substrate preheating, inter-layer dwell as well as post-heat treatment. The processed sample's microstructural characteristics, residual stress, microhardness, and tensile properties are assessed in comparison to the manufacturing strategies. Rapid heat dissipation caused finer microstructure near the substrate. There is a growth of columnar grain structure epitaxially in the build direction. The progressive microstructure change seen in the build direction across the cross-section was due to the gradual rise of heat accumulation between subsequent layers. The inter-dendritic zones contained Laves phases. Laves phases have a high Nb, Mo as well as Si content, according to the EDS spectrum. The FESEM microstructural morphology of the deposited samples after their post-heat treatment has shown a new microstructure with the combination of equiaxed (recrystallized) and columnar dendritic structure with the reconstruction of columnar dendritic solidification microstructure into equiaxed grains. Heat treatment caused the Laves phases to dissolve in the matrix of IN625 alloy, which led to the precipitation of nanometric γ″ phases. The deposition strategies with substrate preheating significantly decreased the residual stress with moderately improved mechanical properties. The combination of substrate preheating, inter-layer dwell, and post-heat treatment has shown an outstanding reduction of residual stress along with a remarkable improvement in tensile strength with the retainment of an equivalent ductility compared with the other strategies.
{"title":"Studies on the Effect of Substrate Preheating, Interlayer Dwell, and Heat Treatment on Microstructure, Residual Stress, and Mechanical Properties of IN625 Superalloy built by Direct Metal Deposition","authors":"Mohsin Khan K, T. B. Rao, R. Mohammed, Manjunath B N, K. Abhinav, Vinod A R","doi":"10.1115/1.4062503","DOIUrl":"https://doi.org/10.1115/1.4062503","url":null,"abstract":"\u0000 In this investigation, IN625 alloy samples were processed by directed energy deposition (DED) under various metal deposition strategies such as substrate preheating, inter-layer dwell, and with combined substrate preheating, inter-layer dwell as well as post-heat treatment. The processed sample's microstructural characteristics, residual stress, microhardness, and tensile properties are assessed in comparison to the manufacturing strategies. Rapid heat dissipation caused finer microstructure near the substrate. There is a growth of columnar grain structure epitaxially in the build direction. The progressive microstructure change seen in the build direction across the cross-section was due to the gradual rise of heat accumulation between subsequent layers. The inter-dendritic zones contained Laves phases. Laves phases have a high Nb, Mo as well as Si content, according to the EDS spectrum. The FESEM microstructural morphology of the deposited samples after their post-heat treatment has shown a new microstructure with the combination of equiaxed (recrystallized) and columnar dendritic structure with the reconstruction of columnar dendritic solidification microstructure into equiaxed grains. Heat treatment caused the Laves phases to dissolve in the matrix of IN625 alloy, which led to the precipitation of nanometric γ″ phases. The deposition strategies with substrate preheating significantly decreased the residual stress with moderately improved mechanical properties. The combination of substrate preheating, inter-layer dwell, and post-heat treatment has shown an outstanding reduction of residual stress along with a remarkable improvement in tensile strength with the retainment of an equivalent ductility compared with the other strategies.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46076290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haifeng Wu, Shan Xu, Hao Chen, Yali Yang, K. Gao, Yongfang Li
An equivalent damage model was established to study the fatigue damage behavior of steel-aluminum friction stir welding (FSW) joints. Internal defects of friction stir welding joint under various cyclic loading stages were observed by X-ray microcomputed tomography (X-CT). For the characteristics of defects of the steel-aluminum FSW joints, a simplified method of defects considering key parameters is proposed and then the defect model is established. The FSW joint model was established based on the steel-aluminum boundary contour identified by using image processing techniques. Based on the defect model and the FSW joint model, the equivalent damage model was developed. The equivalent damage model was subjected to finite element analysis and compared with the test using the strain amplitude as the damage variable. The equivalent damage model can be used to assess fatigue damage in steel-aluminum FSW joints, which provides some theoretical basis for fatigue life prediction.
{"title":"Fatigue Damage Study of Steel-aluminum Friction Stir Welding Joints Based on Equivalent Damage Model","authors":"Haifeng Wu, Shan Xu, Hao Chen, Yali Yang, K. Gao, Yongfang Li","doi":"10.1115/1.4062444","DOIUrl":"https://doi.org/10.1115/1.4062444","url":null,"abstract":"\u0000 An equivalent damage model was established to study the fatigue damage behavior of steel-aluminum friction stir welding (FSW) joints. Internal defects of friction stir welding joint under various cyclic loading stages were observed by X-ray microcomputed tomography (X-CT). For the characteristics of defects of the steel-aluminum FSW joints, a simplified method of defects considering key parameters is proposed and then the defect model is established. The FSW joint model was established based on the steel-aluminum boundary contour identified by using image processing techniques. Based on the defect model and the FSW joint model, the equivalent damage model was developed. The equivalent damage model was subjected to finite element analysis and compared with the test using the strain amplitude as the damage variable. The equivalent damage model can be used to assess fatigue damage in steel-aluminum FSW joints, which provides some theoretical basis for fatigue life prediction.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":"1 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41495842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. A, Rajakumar Selvarajan, Tushar Sonar, M. Ivanov
The joining of Ti6Al4V (Ti64) alloy and AISI 304 austenitic stainless steel (ASS 304) carries significant importance in aero-engines for turbine blade applications. However, it is difficult to join using fusion welding. The fusion welding of Ti64 alloy and ASS 304 steel promotes the evolution of various Fe-Cr-Ti and Fe-Ti intermetallics in weld zone owing to limited solid solubility of Fe, Cr, Ti, and Ni with each other. The evolution of these intermetallics deteriorates the strength properties of joints. Hence for joining Ti6Al4 alloy and ASS 304 steel, vacuum diffusion bonding (VBD) method is employed with thin Copper (Cu) foil as an interlayer. DB pressure extends a significant influence on microstructural evolution and strength of joints. So, for the feasibility of joining Ti alloy and ASS, the effect of DB pressure on microstructure and strength of joints is investigated. Results showed that the dissimilar joints of Ti64 alloy and ASS 304 steel developed using the DB pressure of 14 MPa exhibited greater lap shear strength (LSS) and bonding strength (BS) of 180 MPa and 268 MPa respectively. It is mostly related to improved joining interface coalescence and the development of the ideal bonding width with the least amount of embrittlement consequences. An increase in DB pressure increases the width of diffusion region which favors the development of detrimental intermetallics of Ti-Fe and curtails the strength of dissimilar joints.
{"title":"Influence of Diffusion Bonding Pressure on Microstructural Features and Strength Performance of Dissimilar Ti6Al4V Alloy and AISI 304 Steel Joints using Copper Interlayer","authors":"A. A, Rajakumar Selvarajan, Tushar Sonar, M. Ivanov","doi":"10.1115/1.4062443","DOIUrl":"https://doi.org/10.1115/1.4062443","url":null,"abstract":"\u0000 The joining of Ti6Al4V (Ti64) alloy and AISI 304 austenitic stainless steel (ASS 304) carries significant importance in aero-engines for turbine blade applications. However, it is difficult to join using fusion welding. The fusion welding of Ti64 alloy and ASS 304 steel promotes the evolution of various Fe-Cr-Ti and Fe-Ti intermetallics in weld zone owing to limited solid solubility of Fe, Cr, Ti, and Ni with each other. The evolution of these intermetallics deteriorates the strength properties of joints. Hence for joining Ti6Al4 alloy and ASS 304 steel, vacuum diffusion bonding (VBD) method is employed with thin Copper (Cu) foil as an interlayer. DB pressure extends a significant influence on microstructural evolution and strength of joints. So, for the feasibility of joining Ti alloy and ASS, the effect of DB pressure on microstructure and strength of joints is investigated. Results showed that the dissimilar joints of Ti64 alloy and ASS 304 steel developed using the DB pressure of 14 MPa exhibited greater lap shear strength (LSS) and bonding strength (BS) of 180 MPa and 268 MPa respectively. It is mostly related to improved joining interface coalescence and the development of the ideal bonding width with the least amount of embrittlement consequences. An increase in DB pressure increases the width of diffusion region which favors the development of detrimental intermetallics of Ti-Fe and curtails the strength of dissimilar joints.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44214725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnesium Metal Matrix Composites (MMMCs) have exceptional mechanical and metallurgical characteristics, which has drawn the interest of researchers across the world. In the present research study, an attempt has been made to fabricate WE43 magnesium (Mg) based nanocomposites using Friction stir processing (FSP) after incorporating nano-Titanium carbide(TiC) as a reinforcement. Further, the impact of different FSP variables such as transverse speeds (40 mm/min and 80 mm/min), and tool rotation speeds (900 rpm and 1800rpm) over the metallurgical, wear, and mechanical performance has been studied. The large thermal energy generated by the rotating FSP tool gives rise to the mechanism of dynamic recrystallization and plastic deformation. This contributes to refining the microstructure and improvement in microhardness as per Hall–Patch relation- contributing to prominent grain size refinement and Orowan mechanism strengthening, due to the dispersion of reinforcement particulates. The outcome of the results depicts that the nanocomposite fabricated at a tool rotation speed of 1800 rpm and 80 mm/min transverse shows better mechanical and tribological characteristics than other developed composites and the base alloy. More specifically, the grain size was reduced nearly 12 times, microhardness was 2.58 times higher, and ultimate tensile strength (UTS) was 2.08 times higher when contrasted to the base alloy. Moreover, the un-processed base material was characterized by an adhesive wear mechanism whereas the presence of scratches depicts the abrasive wear mechanism was dominant for WE43/TiC nanocomposite.
{"title":"Fabrication and Characterization of Magnesium-Based WE43/TiC Nanocomposite Material Developed via Friction Stir Processing and Study of Significant Parameters","authors":"","doi":"10.1115/1.4062321","DOIUrl":"https://doi.org/10.1115/1.4062321","url":null,"abstract":"\u0000 Magnesium Metal Matrix Composites (MMMCs) have exceptional mechanical and metallurgical characteristics, which has drawn the interest of researchers across the world. In the present research study, an attempt has been made to fabricate WE43 magnesium (Mg) based nanocomposites using Friction stir processing (FSP) after incorporating nano-Titanium carbide(TiC) as a reinforcement. Further, the impact of different FSP variables such as transverse speeds (40 mm/min and 80 mm/min), and tool rotation speeds (900 rpm and 1800rpm) over the metallurgical, wear, and mechanical performance has been studied. The large thermal energy generated by the rotating FSP tool gives rise to the mechanism of dynamic recrystallization and plastic deformation. This contributes to refining the microstructure and improvement in microhardness as per Hall–Patch relation- contributing to prominent grain size refinement and Orowan mechanism strengthening, due to the dispersion of reinforcement particulates. The outcome of the results depicts that the nanocomposite fabricated at a tool rotation speed of 1800 rpm and 80 mm/min transverse shows better mechanical and tribological characteristics than other developed composites and the base alloy. More specifically, the grain size was reduced nearly 12 times, microhardness was 2.58 times higher, and ultimate tensile strength (UTS) was 2.08 times higher when contrasted to the base alloy. Moreover, the un-processed base material was characterized by an adhesive wear mechanism whereas the presence of scratches depicts the abrasive wear mechanism was dominant for WE43/TiC nanocomposite.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49350996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Both understanding and simulation of the process of corrosion damage are crucial for the prediction of remaining service life of engineering structures, sound reliability analysis, and design for the purpose of enhancing overall resistance of the material to corrosion damage. A coupled mechano-electrochemical PD corrosion model was established by using the peridynamic (PD) corrosion theory and the mechano-chemical effect theory.The model is capable of simulating the occurrence of degradation caused by the conjoint and mutually interactive influences of mechano-electrochemical phenomena. Corrosion behavior of TC18 titanium alloy in EXCO solution under stress loads of 31% σ0.2, 47% σ0.2 and 62% σ0.2 was studied. The effect of tensile loads on the corrosion behavior of TC18 titanium alloy was examined by combining the micromorphology and electrochemical parameters to verify the dependence of reaction rate occurring at the anode on tensile stress. Results of this study shed light as the stress level increases, the corrosion potential of TC18 titanium alloy shifts negatively, the corrosion current density increases and the corrosion intensifies. When the phase transition mechanism is satisfied, boundary movement occurs spontaneously.This model can safely be employed to complex geometric shapes and as a basis for studying crack propagation in environments that are favorable or conducive for inducing corrosion.
{"title":"Study on the Corrosion Behavior and Numerical Simulation of TC18 Titanium Alloy under Tensile Stress","authors":"","doi":"10.1115/1.4062289","DOIUrl":"https://doi.org/10.1115/1.4062289","url":null,"abstract":"\u0000 Both understanding and simulation of the process of corrosion damage are crucial for the prediction of remaining service life of engineering structures, sound reliability analysis, and design for the purpose of enhancing overall resistance of the material to corrosion damage. A coupled mechano-electrochemical PD corrosion model was established by using the peridynamic (PD) corrosion theory and the mechano-chemical effect theory.The model is capable of simulating the occurrence of degradation caused by the conjoint and mutually interactive influences of mechano-electrochemical phenomena. Corrosion behavior of TC18 titanium alloy in EXCO solution under stress loads of 31% σ0.2, 47% σ0.2 and 62% σ0.2 was studied. The effect of tensile loads on the corrosion behavior of TC18 titanium alloy was examined by combining the micromorphology and electrochemical parameters to verify the dependence of reaction rate occurring at the anode on tensile stress. Results of this study shed light as the stress level increases, the corrosion potential of TC18 titanium alloy shifts negatively, the corrosion current density increases and the corrosion intensifies. When the phase transition mechanism is satisfied, boundary movement occurs spontaneously.This model can safely be employed to complex geometric shapes and as a basis for studying crack propagation in environments that are favorable or conducive for inducing corrosion.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48493331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ngoc Fuhr, S. Zhou, Keren Shen, Aseel Rajab, Salim Es-Said, Thaung Shonnu, Skyler Tan, Ryan Riebe, Nathan Santos, Ye Thura Hein, R. Toal, Yong Jun Li, M. Timko, O. Es-Said
This study compares the fatigue performance between the AA2050-T852 alloy and AA7050-T7452 alloy traditionally used in aircraft structures. Rotating beam fatigue tests were performed on AA2050-T852 and AA7050-T7452 specimens cut from forged plates with different orientations and at different thickness levels. The samples were tested at 345 MPa (50 ksi), 276 MPa (40 ksi), 207 MPa (30 ksi) and 172 MPa (25 ksi). Scanning Electron Microscope (SEM) images showed mixed mode in all samples. However, the equiaxed dimples were more abundant and finer in the AA2050-T852 alloy. The results indicated that AA2050-T852 alloy demonstrated better fatigue life performance compared to AA7050-T7452 alloy at almost all stresses. No significant difference in fatigue anisotropy was found in one alloy versus the other.
{"title":"Comparison of Fatigue Life of AA2050-T852 and AA7050-T7452 Alloy Forgings at Different Orientations","authors":"Ngoc Fuhr, S. Zhou, Keren Shen, Aseel Rajab, Salim Es-Said, Thaung Shonnu, Skyler Tan, Ryan Riebe, Nathan Santos, Ye Thura Hein, R. Toal, Yong Jun Li, M. Timko, O. Es-Said","doi":"10.1115/1.4062257","DOIUrl":"https://doi.org/10.1115/1.4062257","url":null,"abstract":"\u0000 This study compares the fatigue performance between the AA2050-T852 alloy and AA7050-T7452 alloy traditionally used in aircraft structures. Rotating beam fatigue tests were performed on AA2050-T852 and AA7050-T7452 specimens cut from forged plates with different orientations and at different thickness levels. The samples were tested at 345 MPa (50 ksi), 276 MPa (40 ksi), 207 MPa (30 ksi) and 172 MPa (25 ksi). Scanning Electron Microscope (SEM) images showed mixed mode in all samples. However, the equiaxed dimples were more abundant and finer in the AA2050-T852 alloy. The results indicated that AA2050-T852 alloy demonstrated better fatigue life performance compared to AA7050-T7452 alloy at almost all stresses. No significant difference in fatigue anisotropy was found in one alloy versus the other.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44153502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objective of this review is double-folded: to show materials scientists, mechanical engineers and reliability physicists not involved in electronics, photonics, micro-electronic-mechanical-systems (MEMS) or MOEMS (optical MEMS) engineering what kind of value they could bring to this important “high-tech” area, as well as to demonstrate to “high-tech” engineers how they could benefit from the application of what has been developed, for many years, in the general field of physical design for reliability of materials and structures employed in various fields of engineering and applied science and what could be effectively applied to their body of knowledge. Accordingly, in the perspective part of the review some critical and even paradoxical, i.e., a-priori non-obvious, problems encountered in microelectronics and photonics materials science, reliability physics and structural analysis are addressed using what could be called analytical (“mathematical”) modeling. The extension part has to do with some specific, mostly aerospace, recent applications of the probabilistic design for reliability concept and analytical modeling effort.
{"title":"Analytical Modeling of Electronic and Photonic Materials Reliability: Perspective and Extension","authors":"E. Suhir","doi":"10.1115/1.4062085","DOIUrl":"https://doi.org/10.1115/1.4062085","url":null,"abstract":"\u0000 The objective of this review is double-folded: to show materials scientists, mechanical engineers and reliability physicists not involved in electronics, photonics, micro-electronic-mechanical-systems (MEMS) or MOEMS (optical MEMS) engineering what kind of value they could bring to this important “high-tech” area, as well as to demonstrate to “high-tech” engineers how they could benefit from the application of what has been developed, for many years, in the general field of physical design for reliability of materials and structures employed in various fields of engineering and applied science and what could be effectively applied to their body of knowledge. Accordingly, in the perspective part of the review some critical and even paradoxical, i.e., a-priori non-obvious, problems encountered in microelectronics and photonics materials science, reliability physics and structural analysis are addressed using what could be called analytical (“mathematical”) modeling. The extension part has to do with some specific, mostly aerospace, recent applications of the probabilistic design for reliability concept and analytical modeling effort.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45281930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we show the development of a numerical model to investigate the 3D interactions between microwave radiation and basalt, granite, and sandstone rock samples. In particular, we assign sample heterogeneity based on the Weibull statistical distribution, and invoke a damage model for elemental tensile and compressive stresses based on the maximum tensile stress and the Mohr-Coulomb theories, respectively. Model implementation is facilitated by the use of COMSOL for use in coupling the electromagnetic, thermal, and solid displacement relations. Various parametric studies are conducted related to variable input power and waveguide port alignment, with model validation conducted with respect to damage resulting from a uniaxial compression test. The results indicate that relatively high induced temperatures will promote damage potential, but its impact must be placed within the context of the sample strength to quantify the true potential damage evolution of a given rock mass. As observed herein, a mechanically weaker rock may be prone to mechanical damage; however, it may also possess a relatively large relative permittivity, enabling it to absorb the least amount of microwave radiation thus yielding comparatively low overall damage profiles compared to a more mechanically competent rock mass.
{"title":"Multiphysics Simulations of Microwave Induced Damage Applied to Rock Samples of Varying Strength and Absorptivity","authors":"J. Allen, Reena Patel, Oliver W. Taylor","doi":"10.1115/1.4056996","DOIUrl":"https://doi.org/10.1115/1.4056996","url":null,"abstract":"\u0000 In this work, we show the development of a numerical model to investigate the 3D interactions between microwave radiation and basalt, granite, and sandstone rock samples. In particular, we assign sample heterogeneity based on the Weibull statistical distribution, and invoke a damage model for elemental tensile and compressive stresses based on the maximum tensile stress and the Mohr-Coulomb theories, respectively. Model implementation is facilitated by the use of COMSOL for use in coupling the electromagnetic, thermal, and solid displacement relations. Various parametric studies are conducted related to variable input power and waveguide port alignment, with model validation conducted with respect to damage resulting from a uniaxial compression test. The results indicate that relatively high induced temperatures will promote damage potential, but its impact must be placed within the context of the sample strength to quantify the true potential damage evolution of a given rock mass. As observed herein, a mechanically weaker rock may be prone to mechanical damage; however, it may also possess a relatively large relative permittivity, enabling it to absorb the least amount of microwave radiation thus yielding comparatively low overall damage profiles compared to a more mechanically competent rock mass.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42297658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Additively manufactured (AM) specimens of 17-4PH stainless steel corresponding to the three-point bend test, compact tension test and single edge cracks were analysed using Extended Finite Element Method (XFEM) approach. A two-dimensional and three-dimensional elastic-plastic simulation were conducted using “Abaqus 6.14” software based on the experimental results and validated with the simulation results. In XFEM, the partition of unity (PU) was used to model a crack in the standard finite element mesh. Based on simulation results, the present study compares the mechanical properties of AM 17-4 PH stainless steel samples with those of wrought 17-4 PH samples. Stress intensity factor and J integral were used to measure fracture toughness of the specimens. The change in fracture toughness with strain rate was evaluated by simulating two-dimensional compact tension specimens. The presence of defects such as pores resulting from entrapped gas, un-melted regions, and powder particles resulting from lack of fusion were the main reasons for lower elongation to failure of LPBF produced 17-4PH SS reported in the literature.
{"title":"XFEM Analysis of Strain Rate Dependent Mechanical Properties of Additively Manufactured 17-4 PH Stainless Steel","authors":"B. Kalita, J. R.","doi":"10.1115/1.4056729","DOIUrl":"https://doi.org/10.1115/1.4056729","url":null,"abstract":"\u0000 Additively manufactured (AM) specimens of 17-4PH stainless steel corresponding to the three-point bend test, compact tension test and single edge cracks were analysed using Extended Finite Element Method (XFEM) approach. A two-dimensional and three-dimensional elastic-plastic simulation were conducted using “Abaqus 6.14” software based on the experimental results and validated with the simulation results. In XFEM, the partition of unity (PU) was used to model a crack in the standard finite element mesh. Based on simulation results, the present study compares the mechanical properties of AM 17-4 PH stainless steel samples with those of wrought 17-4 PH samples. Stress intensity factor and J integral were used to measure fracture toughness of the specimens. The change in fracture toughness with strain rate was evaluated by simulating two-dimensional compact tension specimens. The presence of defects such as pores resulting from entrapped gas, un-melted regions, and powder particles resulting from lack of fusion were the main reasons for lower elongation to failure of LPBF produced 17-4PH SS reported in the literature.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49551447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kellis Kincaid, David W. MacPhee, G. Stubblefield, J. Jordon, T. Rushing, P. Allison
In this study, a finite volume simulation framework was developed, validated, and employed for the first time in a new solid-state additive manufacturing and repair process, Additive Friction Stir Deposition (AFSD). The open-source computational fluid dynamics (CFD) code OpenFOAM was used to simulate the deposition of a single layer of Aluminum Alloy 6061 feedstock onto a substrate, using a viscoplastic model to predict the flow behavior of the material. Conjugate heat transfer was considered between the build layer, the surrounding atmosphere, and the substrate, and the resulting temperatures were validated against experimental data recorded for three processing cases. Excellent agreement between simulated and measured temperature data was obtained, as well as a good qualitative prediction of overall build layer morphology. Further analysis of the temperature field was conducted to reveal the variation of temperature in the build direction, an analysis not possible with previous experimental or numerical methods, as well as a global heat transfer analysis to determine the relative importance of various modes of heat input and cooling. Tool heating was found to be the primary heat input to the system, representing 73% of energy input, while conduction to the substrate was the main mode of part cooling, representing 73% of heat loss from the build layer.
{"title":"A Finite Volume Framework for the Simulation of Additive Friction Stir Deposition","authors":"Kellis Kincaid, David W. MacPhee, G. Stubblefield, J. Jordon, T. Rushing, P. Allison","doi":"10.1115/1.4056642","DOIUrl":"https://doi.org/10.1115/1.4056642","url":null,"abstract":"\u0000 In this study, a finite volume simulation framework was developed, validated, and employed for the first time in a new solid-state additive manufacturing and repair process, Additive Friction Stir Deposition (AFSD). The open-source computational fluid dynamics (CFD) code OpenFOAM was used to simulate the deposition of a single layer of Aluminum Alloy 6061 feedstock onto a substrate, using a viscoplastic model to predict the flow behavior of the material. Conjugate heat transfer was considered between the build layer, the surrounding atmosphere, and the substrate, and the resulting temperatures were validated against experimental data recorded for three processing cases. Excellent agreement between simulated and measured temperature data was obtained, as well as a good qualitative prediction of overall build layer morphology. Further analysis of the temperature field was conducted to reveal the variation of temperature in the build direction, an analysis not possible with previous experimental or numerical methods, as well as a global heat transfer analysis to determine the relative importance of various modes of heat input and cooling. Tool heating was found to be the primary heat input to the system, representing 73% of energy input, while conduction to the substrate was the main mode of part cooling, representing 73% of heat loss from the build layer.","PeriodicalId":15700,"journal":{"name":"Journal of Engineering Materials and Technology-transactions of The Asme","volume":" ","pages":""},"PeriodicalIF":1.2,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42631649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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