The present work deals with the fabrication of AA7068 as a matrix reinforced with different weight percentages of titanium carbide (0, 0.5, 1, 1.5, 2, and 2.5) % and with a constant weight percentage of graphene of 1 % using the stir casting method. The objective of this work is to study the mechanical and tribological properties of the hybrid composite. The uniform distribution of graphene and titanium carbide particles in the AA7068 matrix was validated with SEM investigations of the manufactured composite. A tensile test was performed, and a maximum ultimate tensile strength (UTS) of 199 MPa and a low percentage of elongation of 4.42 were obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. The hardness of the composite was measured using a Rockwell hardness tester, and a maximum value of 63 HRB was obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. The hardness increased as the percentage of TiC increased. The impact strength was determined with a Charpy test, and a maximum value of 4.5 J was obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. A dry sliding wear test was performed in a pin-on-disc wear testing machine with different loads (5, 10 and 15) N, a constant sliding speed of 1000 min–1, and a sliding distance of 1000 m. The sample having 2.5 w/% TiC had a lower coefficient of friction and lower wear loss under different load conditions. Due to the presence of graphene and TiC reinforcements, the composites’ tensile, hardness and tribological properties improved significantly when compared to the aluminium alloy 7068 matrix.
{"title":"HYBRID COMPOSITES REINFORCED WITH GRAPHENE AND TITANIUM CARBIDE IN AA7068 MATRIX: EVALUATION OF MECHANICAL AND TRIBOLOGICAL PROPERTY","authors":"Naganambi Nambirajan, None Selvakumar N.","doi":"10.17222/mit.2023.915","DOIUrl":"https://doi.org/10.17222/mit.2023.915","url":null,"abstract":"The present work deals with the fabrication of AA7068 as a matrix reinforced with different weight percentages of titanium carbide (0, 0.5, 1, 1.5, 2, and 2.5) % and with a constant weight percentage of graphene of 1 % using the stir casting method. The objective of this work is to study the mechanical and tribological properties of the hybrid composite. The uniform distribution of graphene and titanium carbide particles in the AA7068 matrix was validated with SEM investigations of the manufactured composite. A tensile test was performed, and a maximum ultimate tensile strength (UTS) of 199 MPa and a low percentage of elongation of 4.42 were obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. The hardness of the composite was measured using a Rockwell hardness tester, and a maximum value of 63 HRB was obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. The hardness increased as the percentage of TiC increased. The impact strength was determined with a Charpy test, and a maximum value of 4.5 J was obtained for the AA7068-1.0 w/% graphene-2.5 w/% TiC composite. A dry sliding wear test was performed in a pin-on-disc wear testing machine with different loads (5, 10 and 15) N, a constant sliding speed of 1000 min–1, and a sliding distance of 1000 m. The sample having 2.5 w/% TiC had a lower coefficient of friction and lower wear loss under different load conditions. Due to the presence of graphene and TiC reinforcements, the composites’ tensile, hardness and tribological properties improved significantly when compared to the aluminium alloy 7068 matrix.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135739792","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}
Mthabisi Talent George Moyo, Terin Adali, Oğuz Han Edebal, Ece Bayir, Aylin Şendemir
Thrombogenesis is an important issue that causes blood-contacting biomedical device failure. This study focuses on hemocompatibility studies of novel blood-contacting polyelectrolyte complexes (PECs) for biomedical application designs. PEC films were fabricated from biobased polymers of silk fibroin (SF), chitosan (CH), and sodium alginate (AL) through the solvent casting method as well as Layer-by-Layer (LbL) technique. Characterization was carried out by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), and Differential scanning calorimetry (DSC) analyses. FTIR spectra displayed all layers’ characteristic peaks of SF, CH, and AL. AFM images indicated that the addition of AL as an outer layer increased surface roughness. DSC analysis suggested that the best thermal stability has been observed with the CH outer layer of PECs. SEM micrograph analysis indicated that the morphologies of PECs were affected by the inclusion of the clopidogrel bisulfate (CLB). Hemocompatibility properties were investigated by complete blood count (CBC), prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), platelet adhesion, erythrocyte morphology analysis, in vitro cholesterol, and albumin level tests. These hemocompatibility analyses demonstrated that the PEC surfaces provide favourable principles to design and develop non-thrombogenic PECs for blood-contacting biomedical applications
{"title":"HEMOCOMPATIBILITY STUDIES OF LAYER-BY-LAYER POLYELECTROLYTE COMPLEXES FOR BIO-BASED POLYMERS","authors":"Mthabisi Talent George Moyo, Terin Adali, Oğuz Han Edebal, Ece Bayir, Aylin Şendemir","doi":"10.17222/mit.2023.922","DOIUrl":"https://doi.org/10.17222/mit.2023.922","url":null,"abstract":"Thrombogenesis is an important issue that causes blood-contacting biomedical device failure. This study focuses on hemocompatibility studies of novel blood-contacting polyelectrolyte complexes (PECs) for biomedical application designs. PEC films were fabricated from biobased polymers of silk fibroin (SF), chitosan (CH), and sodium alginate (AL) through the solvent casting method as well as Layer-by-Layer (LbL) technique. Characterization was carried out by Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), and Differential scanning calorimetry (DSC) analyses. FTIR spectra displayed all layers’ characteristic peaks of SF, CH, and AL. AFM images indicated that the addition of AL as an outer layer increased surface roughness. DSC analysis suggested that the best thermal stability has been observed with the CH outer layer of PECs. SEM micrograph analysis indicated that the morphologies of PECs were affected by the inclusion of the clopidogrel bisulfate (CLB). Hemocompatibility properties were investigated by complete blood count (CBC), prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT), platelet adhesion, erythrocyte morphology analysis, in vitro cholesterol, and albumin level tests. These hemocompatibility analyses demonstrated that the PEC surfaces provide favourable principles to design and develop non-thrombogenic PECs for blood-contacting biomedical applications","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744496","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}
This present study examines the wetting behavior of N-type silicon surfaces that have been textured using a femtosecond laser. By employing three different patterns, i.e., square pillars, micro dimples, and circumferential grooves, and manipulating key femtosecond laser parameters such as laser power (ranging from 8 W to 12 W) and repetitions (ranging from 40 to 60), the wettability properties of the silicon surfaces are modified. The wettability properties of the surface were evaluated by measuring the contact angle by the sessile-drop method using distilled deionized water as a testing liquid. The textured surfaces displayed various wettability characteristics, varying from hydrophilic to hydrophobic. The hydrophobic behavior was observed on surfaces with a peak laser power of 12 W, 60 repetitions, and the lowest pitch of 160 µm. For the square pillar and micro-dimple textures, contact angles of 146° and 120°, respectively, were measured. Conversely, the circumferential grooves exhibited hydrophilic behavior with a contact angle of 20°. These results were achieved at laser powers of 10 W and 8 W, higher pitch values, and increased repetitions. The contact angle decreased with an increase in pitch and a decrease in repetitions and laser power. Based on the experimental findings, it can be concluded that the wettability of silicon surfaces can be controlled for specific applications using a single-step laser ablation technique. The desired wettability characteristics can be achieved by carefully adjusting the key femtosecond-laser parameters and geometrical features.
{"title":"WETTABILITY STUDIES ON FEMTOSECOND-¬LASER-TEXTURED N-TYPE SILICON SURFACES","authors":"Srikanth Vipparla, Samuel G.L., Dongbin Wei","doi":"10.17222/mit.2023.838","DOIUrl":"https://doi.org/10.17222/mit.2023.838","url":null,"abstract":"This present study examines the wetting behavior of N-type silicon surfaces that have been textured using a femtosecond laser. By employing three different patterns, i.e., square pillars, micro dimples, and circumferential grooves, and manipulating key femtosecond laser parameters such as laser power (ranging from 8 W to 12 W) and repetitions (ranging from 40 to 60), the wettability properties of the silicon surfaces are modified. The wettability properties of the surface were evaluated by measuring the contact angle by the sessile-drop method using distilled deionized water as a testing liquid. The textured surfaces displayed various wettability characteristics, varying from hydrophilic to hydrophobic. The hydrophobic behavior was observed on surfaces with a peak laser power of 12 W, 60 repetitions, and the lowest pitch of 160 µm. For the square pillar and micro-dimple textures, contact angles of 146° and 120°, respectively, were measured. Conversely, the circumferential grooves exhibited hydrophilic behavior with a contact angle of 20°. These results were achieved at laser powers of 10 W and 8 W, higher pitch values, and increased repetitions. The contact angle decreased with an increase in pitch and a decrease in repetitions and laser power. Based on the experimental findings, it can be concluded that the wettability of silicon surfaces can be controlled for specific applications using a single-step laser ablation technique. The desired wettability characteristics can be achieved by carefully adjusting the key femtosecond-laser parameters and geometrical features.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744348","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}
Senthilkumar G., V. Vinodkumar, T. Mayavan, G. Rathinasabapathi
High-temperature applications such as heat exchangers and burner tubes employ AISI 430 steel. A larger heat-affected zone, undesired metallurgical changes and higher hardness in the weld area occur when fusion welding this type of steel. The study investigates the feasibility of welding ferritic stainless steel AISI 430, utilizing a solid-state method (continuous drive friction welding). The experiment uses an L27 orthogonal array and three levels of variation in the welding parameters such as frictional pressure, forging pressure, friction time, forging time and rotational speed. Tensile strength, axial shortening and impact toughness are the observed quality characteristics. In an integrated approach of the grey incidence reinforced response surface methodology, the benefits of the grey relational theory are merged with the statistical analysis of the response surface methodology to determine the ideal friction welding inputs (frictional pressure – 59.95 MPa, friction time – 4 s, upset pressure – 68.5 MPa, forging time – 3 s and rotational speed – 1399 min–1). The AISI 430 steel joint’s qualities are improved by 2.25, 12.74 and 7.89 % in terms of the maximum ultimate tensile strength, axial shortening and impact toughness, respectively.
{"title":"OPTIMIZATION OF PROCESS PARAMETERS FOR A SOLID-STATE-WELDED AISI 430 STEEL JOINT WITH THE GRG REINFORCED RESPONSE SURFACE METHODOLOGY","authors":"Senthilkumar G., V. Vinodkumar, T. Mayavan, G. Rathinasabapathi","doi":"10.17222/mit.2023.873","DOIUrl":"https://doi.org/10.17222/mit.2023.873","url":null,"abstract":"High-temperature applications such as heat exchangers and burner tubes employ AISI 430 steel. A larger heat-affected zone, undesired metallurgical changes and higher hardness in the weld area occur when fusion welding this type of steel. The study investigates the feasibility of welding ferritic stainless steel AISI 430, utilizing a solid-state method (continuous drive friction welding). The experiment uses an L27 orthogonal array and three levels of variation in the welding parameters such as frictional pressure, forging pressure, friction time, forging time and rotational speed. Tensile strength, axial shortening and impact toughness are the observed quality characteristics. In an integrated approach of the grey incidence reinforced response surface methodology, the benefits of the grey relational theory are merged with the statistical analysis of the response surface methodology to determine the ideal friction welding inputs (frictional pressure – 59.95 MPa, friction time – 4 s, upset pressure – 68.5 MPa, forging time – 3 s and rotational speed – 1399 min–1). The AISI 430 steel joint’s qualities are improved by 2.25, 12.74 and 7.89 % in terms of the maximum ultimate tensile strength, axial shortening and impact toughness, respectively.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744866","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}
Inhomogeneous grain size is a significant structural defect in large forgings. This study employed cellular automata to simulate the dynamic recrystallization (DRX) of 316LN steel and analyzed the grain distribution during DRX. The accuracy of the CA method was verified by comparing its results with the results of a thermal simulation test on Gleeble 1500D. Subsequently, a novel method for evaluating grain size inhomogeneity was proposed. The grain size inhomogeneity coefficient Gu was introduced to determine the evolution of grain size inhomogeneity during DRX. This coefficient accurately and objectively reflects grain inhomogeneity. The impact of the initial and recrystallized grain size on the inhomogeneity during DRX was also analyzed.
{"title":"PREDICTION OF MICROSTRUCTURE EVOLUTION OF 316LN AUSTENITIC STAINLESS STEEL USING CELLULAR AUTOMATA AND A NOVEL EVALUATION METHOD FOR GRAIN SIZE INHOMOGENEITY","authors":"Min Qin, Jiansheng Liu","doi":"10.17222/mit.2023.796","DOIUrl":"https://doi.org/10.17222/mit.2023.796","url":null,"abstract":"Inhomogeneous grain size is a significant structural defect in large forgings. This study employed cellular automata to simulate the dynamic recrystallization (DRX) of 316LN steel and analyzed the grain distribution during DRX. The accuracy of the CA method was verified by comparing its results with the results of a thermal simulation test on Gleeble 1500D. Subsequently, a novel method for evaluating grain size inhomogeneity was proposed. The grain size inhomogeneity coefficient Gu was introduced to determine the evolution of grain size inhomogeneity during DRX. This coefficient accurately and objectively reflects grain inhomogeneity. The impact of the initial and recrystallized grain size on the inhomogeneity during DRX was also analyzed.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135739787","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}
Shu Cui, Haixin Zhao, Chengyou Liu, Hai Yu, Nan Li, Xiaotian Li
A CeO2@Ag hollow spherical composite catalyst was synthesized with the template method. Firstly, a SiO2@CeO2 core-shell structure was synthesized using SiO2 spheres as the template, and then the SiO2 core was removed by etching to obtain hollow CeO2 spheres. The CeO2 hollow microspheres have a large specific surface area, which can effectively suppress the aggregation of Ag nanoparticles, leading to CeO2@Ag with a regular morphology and well dispersed Ag nanoparticles. There is a strong synergistic effect between CeO2 and Ag, which is beneficial to improving the catalytic performance. As a result, the CeO2@Ag hollow spherical composite catalyst can reduce 4-nitrophenol efficiently.
{"title":"SYNTHESIS, CHARACTERIZATION OF CeO2@Ag HOLLOW SPHERES AND EVALUATION OF THEIR CATALYST ACTIVITY FOR THE REDUCTION OF 4-NP","authors":"Shu Cui, Haixin Zhao, Chengyou Liu, Hai Yu, Nan Li, Xiaotian Li","doi":"10.17222/mit.2023.813","DOIUrl":"https://doi.org/10.17222/mit.2023.813","url":null,"abstract":"A CeO2@Ag hollow spherical composite catalyst was synthesized with the template method. Firstly, a SiO2@CeO2 core-shell structure was synthesized using SiO2 spheres as the template, and then the SiO2 core was removed by etching to obtain hollow CeO2 spheres. The CeO2 hollow microspheres have a large specific surface area, which can effectively suppress the aggregation of Ag nanoparticles, leading to CeO2@Ag with a regular morphology and well dispersed Ag nanoparticles. There is a strong synergistic effect between CeO2 and Ag, which is beneficial to improving the catalytic performance. As a result, the CeO2@Ag hollow spherical composite catalyst can reduce 4-nitrophenol efficiently.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135739791","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}
Metallic foams have gained popularity in industrial applications and research due to their unique mechanical properties combined with light weight, vibroacoustic damping and high-temperature resistance. Generally, closed-cell foams have poor sound absorption properties due to their closed cellular structure when compared to open-cell foams. This paper investigates a new composite closed-cell foam for its acoustic properties. The new closed-cell aluminium fly-ash foam was made with liquid processing, using calcium carbonate (CaCO3) as the blowing agent. The effects of the fly-ash content on the cell morphology and mechanical properties were analyzed. Acoustic studies were conducted on the prepared closed-cell foam using the impedance tube method. Samples were prepared in different ways to determine the effects of the changing parameters. The results of quasi-static compression and microstructural analyses of two different combinations of the foam revealed small pore sizes with varying relative densities and compressive strengths. It is evident from the acoustic studies that the foams are capable of improved sound absorption of medium and high frequencies.
{"title":"A STUDY ON SOUND-ABSORPTION ABILITY OF CLOSED-CELL ALUMINIUM FOAMS","authors":"Vaddi Thulasikanth, Padmanabhan Raghupathy","doi":"10.17222/mit.2023.741","DOIUrl":"https://doi.org/10.17222/mit.2023.741","url":null,"abstract":"Metallic foams have gained popularity in industrial applications and research due to their unique mechanical properties combined with light weight, vibroacoustic damping and high-temperature resistance. Generally, closed-cell foams have poor sound absorption properties due to their closed cellular structure when compared to open-cell foams. This paper investigates a new composite closed-cell foam for its acoustic properties. The new closed-cell aluminium fly-ash foam was made with liquid processing, using calcium carbonate (CaCO3) as the blowing agent. The effects of the fly-ash content on the cell morphology and mechanical properties were analyzed. Acoustic studies were conducted on the prepared closed-cell foam using the impedance tube method. Samples were prepared in different ways to determine the effects of the changing parameters. The results of quasi-static compression and microstructural analyses of two different combinations of the foam revealed small pore sizes with varying relative densities and compressive strengths. It is evident from the acoustic studies that the foams are capable of improved sound absorption of medium and high frequencies.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744164","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}
Implant design developed considerably with the advancement of restorative dentistry. Examining the stress distribution in the cancellous and cortical bones around custom-made implants with different thread-profile models is the study’s objective. The newly designed implants were made with a diameter and length of 4.5 mm and 11.5 mm. The implants were designed the same, but had different thread profiles. Model A is designed with a standard V-shape thread design, and it was compared with the remaining three dental implants (models B, C, and D) having different customized thread-profile designs. The biomechanical characteristics of the four implant models were compared with the use of biomechanical profiling to predict the mechanical performance of various dental-screw models, including the influence of physiological factors. The stress distribution in the D4 bone area of implants with different thread-profile designs under a vertical load of 100 N at 0° and an oblique load of 223.6 N at 25° was examined using ANSYS Workbench. The trabecular and cortical bones comprise the structure of the D4 bone area. Deformation and stress (von Mises) findings were found for the dental implants and bone. While implant models C and D showed less stress distribution in the cortical and cancellous bone, they nonetheless produced outcomes superior to those of the conventional model A underloading. According to the findings, the unique dental implant design lessens the stress concentration in the cortical bone’s neck area. The suggested model C increases the implant’s stability in that region by distributing a low stress over the D4 bone.
{"title":"BIOMECHANICAL ANALYSIS OF AN OPTIMIZED PATIENT-SPECIFIC DENTAL-IMPLANT SCREW IN THE POSTERIOR MANDIBLE","authors":"N. Selvakumar, Balamurugan P.","doi":"10.17222/mit.2023.907","DOIUrl":"https://doi.org/10.17222/mit.2023.907","url":null,"abstract":"Implant design developed considerably with the advancement of restorative dentistry. Examining the stress distribution in the cancellous and cortical bones around custom-made implants with different thread-profile models is the study’s objective. The newly designed implants were made with a diameter and length of 4.5 mm and 11.5 mm. The implants were designed the same, but had different thread profiles. Model A is designed with a standard V-shape thread design, and it was compared with the remaining three dental implants (models B, C, and D) having different customized thread-profile designs. The biomechanical characteristics of the four implant models were compared with the use of biomechanical profiling to predict the mechanical performance of various dental-screw models, including the influence of physiological factors. The stress distribution in the D4 bone area of implants with different thread-profile designs under a vertical load of 100 N at 0° and an oblique load of 223.6 N at 25° was examined using ANSYS Workbench. The trabecular and cortical bones comprise the structure of the D4 bone area. Deformation and stress (von Mises) findings were found for the dental implants and bone. While implant models C and D showed less stress distribution in the cortical and cancellous bone, they nonetheless produced outcomes superior to those of the conventional model A underloading. According to the findings, the unique dental implant design lessens the stress concentration in the cortical bone’s neck area. The suggested model C increases the implant’s stability in that region by distributing a low stress over the D4 bone.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743918","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 present work aims to investigate the effect of cutting-tool edge geometry on cutting force and surface finish while machining an Al6061 alloy under different conditions. A series of experiments was performed with a custom-fabricated cutting insert of a chamfered edge to observe the effect of feed rate and depth of cut on the cutting forces and surface finish. The results showed that varying the cutting-edge geometry has a significant effect on controlling the cutting forces. Also, as the feed and depth of cut were reduced (at high cutting speeds), the surface roughness was observed to reduce with the geometry effect. Furthermore, in the present work validation of the experimental results were also performed based on a multi-criteria decision-making method called Grey Relational Analysis (GRA). The weighted GRA predicted the optimal combination of machining parameters for two different cutting-tool inserts. Finally, the obtained optimal results were compared with the predicted and experimental values in terms of weighted GRG. The result shows that there was no significant improvement while using the standard cutting tool, whereas a net improvement of 16.9 % was observed while using the chamfered cutting tool for machining the Al 6061 alloy.
{"title":"PREDICTING THE OPTIMAL PARAMETERS BY MULTI-OBJECTIVE DECISION MAKING WHILE MACHINING AN Al6061 ALLOY USING CBN INSERTS WITH DIFFERENT CUTTING-EDGE GEOMETRIES","authors":"I Sri Phani Sushma, Samuel G.L., Gyula Varga","doi":"10.17222/mit.2023.830","DOIUrl":"https://doi.org/10.17222/mit.2023.830","url":null,"abstract":"The present work aims to investigate the effect of cutting-tool edge geometry on cutting force and surface finish while machining an Al6061 alloy under different conditions. A series of experiments was performed with a custom-fabricated cutting insert of a chamfered edge to observe the effect of feed rate and depth of cut on the cutting forces and surface finish. The results showed that varying the cutting-edge geometry has a significant effect on controlling the cutting forces. Also, as the feed and depth of cut were reduced (at high cutting speeds), the surface roughness was observed to reduce with the geometry effect. Furthermore, in the present work validation of the experimental results were also performed based on a multi-criteria decision-making method called Grey Relational Analysis (GRA). The weighted GRA predicted the optimal combination of machining parameters for two different cutting-tool inserts. Finally, the obtained optimal results were compared with the predicted and experimental values in terms of weighted GRG. The result shows that there was no significant improvement while using the standard cutting tool, whereas a net improvement of 16.9 % was observed while using the chamfered cutting tool for machining the Al 6061 alloy.","PeriodicalId":18258,"journal":{"name":"Materiali in tehnologije","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135744511","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}
Mervat Youssef, Eman El-Shenawy, Wael Khair-Eldeen, Tadaharu Adachi, Adel Nofal, Mohsen A. Hassan
With this work we successfully developed two modified Armox 500T alloys using microalloying with different amounts of niobium (Nb) and boron (B) to obtain a finer grain size, which in return enhances the remnant properties. Furthermore, different heat-treatment cycles were designed and performed using a quenching dilatometer to study the combined effect of thermal cycling and microalloying with Nb and B on the microstructure and transformation temperatures including the start and finish temperature of the austenite transformation (Ac1, Ac3) and the martensite start and finish temperature (Ms, Mf) of the investigated alloys. Dilatometry results show that increasing the content of Nb from 0.07 w/% to 0.13 w/% and B from 0.0035 to 0.0046 w/% increases the temperature range between Ac1 and Ac3 by 55 °C, indicating a broader range for changing heat-treatment temperatures. In addition, the Ms temperature is reduced by 13 °C due to austenite refinement caused by the microalloying of Nb and B. The effect of the annealing temperature at a constant heating rate showed a significant impact on the austenite grain size and hardness. Furthermore, the kinetics of phase transformations were theoretically studied using Thermo-Calc, and the numerical predictions were confirmed experimentally with dilatometry results. Metallography investigations using a scanning electron microscope (SEM) and an optical microscope (OM) were conducted to evaluate the microstructure evolution of the developed alloys. Hardness tests were performed to evaluate the effect of the grain refinement of martensite lathes caused by microalloying with Nb, B, and heat-treatment thermal cycling. It is found that the hardness of the modified Armox alloys in this research was improved by 14 % in comparison with the conventional Armox 500T.
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