In this study, 7075-T651 Al alloys were joined by friction stir welding (FSW) at a fixed rotational speed and different welding speeds. The stirring tool used in the welding processes was comprised of a shoulder of 20 mm in diameter and modified M6 × 1 HSS hand taps used as pins. The FSW was performed at a rotational speed of 1600 rpm and at welding speeds of 20, 40, and 60 mmmin−1. Mechanical and metallographic tests were carried out on the welded joints and the effects of the welding speed on the mechanical and metallurgical properties of the welded specimens were investigated. Welding speed significantly affected the microstructure and mechanical properties of the joining. Results showed that the average grain size of the weld nugget was reduced as welding speed was increased. In addition, it was found that high welding speed negatively affected the mechanical properties of the weld nugget. K e y w o r d s: FSW, aluminium alloy, mechanical properties, micro defects, microstructure
{"title":"Effect of welding speed on the mechanical properties and weld defects of 7075 Al alloy joined by FSW","authors":"B. Çevik, Y. Özçatalbaş, B. Gülenç","doi":"10.4149/KM_2016_3_241","DOIUrl":"https://doi.org/10.4149/KM_2016_3_241","url":null,"abstract":"In this study, 7075-T651 Al alloys were joined by friction stir welding (FSW) at a fixed rotational speed and different welding speeds. The stirring tool used in the welding processes was comprised of a shoulder of 20 mm in diameter and modified M6 × 1 HSS hand taps used as pins. The FSW was performed at a rotational speed of 1600 rpm and at welding speeds of 20, 40, and 60 mmmin−1. Mechanical and metallographic tests were carried out on the welded joints and the effects of the welding speed on the mechanical and metallurgical properties of the welded specimens were investigated. Welding speed significantly affected the microstructure and mechanical properties of the joining. Results showed that the average grain size of the weld nugget was reduced as welding speed was increased. In addition, it was found that high welding speed negatively affected the mechanical properties of the weld nugget. K e y w o r d s: FSW, aluminium alloy, mechanical properties, micro defects, microstructure","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78806233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, effects of alloying elements and different heat treatment processes on the properties of DIN 1.3243, DIN 1.3343 and ASP 2052 were investigated. Austenitizing and tempering temperatures are critical parameters for the hardening of steels. Also, alloying elements have critical effect on microstructure and mechanical properties of steels. Various austenitizing temperatures with two tempering temperatures were implemented to samples. Effects of alloying elements, process parameters on the mechanical properties and tooling abilities of the specimens were investigated. Rockwell hardness tests were carried out on specimens, and their tooling abilities were characterized by the number of screws that were fabricated with specimens. According to the results of experiments, higher hardness values were obtained for elevated austenitizing temperatures. Besides, higher hardness values were obtained due to presence of alloying elements and formation of secondary carbides during tempering process. Moreover, tooling ability of the specimens increased with higher hardness values and formation of alloy carbides. Hot work properties of specimens were evolved by Co. K e y w o r d s: high speed steels, hardness test, hardening, tempering
{"title":"Effects of alloying elements with various heat treatment processes on the properties of high speed steels","authors":"A. Kisasoz, G. O. Toptop, A. Karaaslan","doi":"10.4149/KM.2013.3.205","DOIUrl":"https://doi.org/10.4149/KM.2013.3.205","url":null,"abstract":"In this study, effects of alloying elements and different heat treatment processes on the properties of DIN 1.3243, DIN 1.3343 and ASP 2052 were investigated. Austenitizing and tempering temperatures are critical parameters for the hardening of steels. Also, alloying elements have critical effect on microstructure and mechanical properties of steels. Various austenitizing temperatures with two tempering temperatures were implemented to samples. Effects of alloying elements, process parameters on the mechanical properties and tooling abilities of the specimens were investigated. Rockwell hardness tests were carried out on specimens, and their tooling abilities were characterized by the number of screws that were fabricated with specimens. According to the results of experiments, higher hardness values were obtained for elevated austenitizing temperatures. Besides, higher hardness values were obtained due to presence of alloying elements and formation of secondary carbides during tempering process. Moreover, tooling ability of the specimens increased with higher hardness values and formation of alloy carbides. Hot work properties of specimens were evolved by Co. K e y w o r d s: high speed steels, hardness test, hardening, tempering","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86085973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the last decade novel computational methods have been introduced in some fields of engineering sciences. In this article, we describe a novel Particle Swarm Optimization (PSO) approach to multi-objective optimization, called Time Variant Multi-Objective Particle Swarm Optimization (TV-MOPSO). The mechanical and tribological behaviors of sintered steel have been experimentally investigated. TV-MOPSO is made adaptive in nature by allowing its vital parameters to change with iterations. This adaptiveness helps the algorithm to explore the search space more efficiently. A new diversity parameter has been used to ensure sufficient diversity amongst the solutions of the non-dominated fronts, while retaining at the same time the convergence to the Pareto-optimal front. K e y w o r d s: wear, steel, swarm
{"title":"The performance of TV-MOPSO in optimization of sintered steels","authors":"A. Mazahery, M. Shabani","doi":"10.4149/km_2013_6_333","DOIUrl":"https://doi.org/10.4149/km_2013_6_333","url":null,"abstract":"During the last decade novel computational methods have been introduced in some fields of engineering sciences. In this article, we describe a novel Particle Swarm Optimization (PSO) approach to multi-objective optimization, called Time Variant Multi-Objective Particle Swarm Optimization (TV-MOPSO). The mechanical and tribological behaviors of sintered steel have been experimentally investigated. TV-MOPSO is made adaptive in nature by allowing its vital parameters to change with iterations. This adaptiveness helps the algorithm to explore the search space more efficiently. A new diversity parameter has been used to ensure sufficient diversity amongst the solutions of the non-dominated fronts, while retaining at the same time the convergence to the Pareto-optimal front. K e y w o r d s: wear, steel, swarm","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89437329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, ultrafine (0.3 µ m) aluminum oxide (Al 2 O 3 ) particles were dispersed into commercially pure magnesium powder using the sonication method and processed by press-sinter-extrusion technique. The oxide particles dispersion in the processed magnesium microstructure was reasonably homogeneous and with good interfacial integrity. The dispersed oxide particles refined the grain morphology. They significantly improved the hardness, yield strength, tensile strength, ductility, and work-of-fracture of magnesium when added to a vol.% of up to 2.5. The dispersed oxide particles also changed the fracture mode of magnesium from brittle to ductile nature. However, the study also revealed that the ultrafine oxide particles dispersion was most effective in improving the overall mechanical properties of magnesium when added in an amount of 0.7 vol.%.
{"title":"Oxide dispersion strengthened magnesium: Effect of sonicated dispersion on the microstructure and mechanical properties","authors":"S. Hassan","doi":"10.4149/KM_2021_1_1","DOIUrl":"https://doi.org/10.4149/KM_2021_1_1","url":null,"abstract":"In this study, ultrafine (0.3 µ m) aluminum oxide (Al 2 O 3 ) particles were dispersed into commercially pure magnesium powder using the sonication method and processed by press-sinter-extrusion technique. The oxide particles dispersion in the processed magnesium microstructure was reasonably homogeneous and with good interfacial integrity. The dispersed oxide particles refined the grain morphology. They significantly improved the hardness, yield strength, tensile strength, ductility, and work-of-fracture of magnesium when added to a vol.% of up to 2.5. The dispersed oxide particles also changed the fracture mode of magnesium from brittle to ductile nature. However, the study also revealed that the ultrafine oxide particles dispersion was most effective in improving the overall mechanical properties of magnesium when added in an amount of 0.7 vol.%.","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88544718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the present study, laser brazing of austenitic stainless steel (type 321) and martensitic stainless steel (type 410) have been performed using 400W pulsed Nd:YAG laser with silverbased filler metal. The microstructure was investigated using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The laser brazed joints consist of α-Ag solid solution, α′-Cu solid solution surrounded by the α-Ag solid solution and eutectic structure. Filler metal shows better spreading on 321 stainless steel because of more content of Ni and presence of Ti as an activator in the alloy. The average thickness of reaction layer is approximately 3.2 μm for 321 stainless steel and 2.2 μm for 410 stainless steel. The tensile strength of 321 stainless steel joints is higher than that of 410 stainless steel joints due to higher thickness of reaction layer, more spreading and smaller wetting angle. The average of micro hardness for joints in a seam is approximately 146 HV. K e y w o r d s: plaser brazing, 321 stainless steel, 410 stainless steel, silver-based filler metal, pulsed Nd:YAG laser
{"title":"Comparative study on laser brazing of austenitic and martensitic stainless steels with silver-based filler metal","authors":"A. Khorram, M. Ghoreishi, M. J., H. Rahimi","doi":"10.4149/km_2014_1_43","DOIUrl":"https://doi.org/10.4149/km_2014_1_43","url":null,"abstract":"In the present study, laser brazing of austenitic stainless steel (type 321) and martensitic stainless steel (type 410) have been performed using 400W pulsed Nd:YAG laser with silverbased filler metal. The microstructure was investigated using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). The laser brazed joints consist of α-Ag solid solution, α′-Cu solid solution surrounded by the α-Ag solid solution and eutectic structure. Filler metal shows better spreading on 321 stainless steel because of more content of Ni and presence of Ti as an activator in the alloy. The average thickness of reaction layer is approximately 3.2 μm for 321 stainless steel and 2.2 μm for 410 stainless steel. The tensile strength of 321 stainless steel joints is higher than that of 410 stainless steel joints due to higher thickness of reaction layer, more spreading and smaller wetting angle. The average of micro hardness for joints in a seam is approximately 146 HV. K e y w o r d s: plaser brazing, 321 stainless steel, 410 stainless steel, silver-based filler metal, pulsed Nd:YAG laser","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75501314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of solidification rate and alloying elements on structure, mechanical and electrical properties of Al-Cu-X alloys","authors":"A. Kalkanoglu, H. Kaya, U. Buyuk, E. Çadırlı","doi":"10.4149/km_2021_5_333","DOIUrl":"https://doi.org/10.4149/km_2021_5_333","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"30 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77511451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, tribological performances of three alloys, 316 L, Ti6Al4V, and CoCrMo, used in manufacturing orthopedic implants, are compared. Wear tests were conducted on a reciprocating wear tester by rubbing an Al2O3 ball. It was found that the wear resistance of the 316 L and CoCrMo alloy was almost 2 and 24 times of the Ti6Al4V alloy, respectively, whose steady state friction coefficient lies between those of the 316 L and CoCrMo alloy. Examinations of wear tracks and contact surfaces of the Al2O3 ball revealed the dominant wear mechanisms as abrasive for CoCrMo and adhesive for 316 L and Ti6Al4V alloy. These observations confirmed that the favorably biocompatible characteristics of Ti6Al4V alloy was not accompanied by a reasonable sliding contact performance. In this respect, surface modification is a necessity for load bearing Ti6Al4V implants to extend their durability in the human body to the levels of 316 L and/or CoCrMo implants. K e y w o r d s: CoCrMo, 316 L, Ti6Al4V, wear
{"title":"Sliding wear performances of 316 L, Ti6Al4V, and CoCrMo alloys","authors":"E. Atar","doi":"10.4149/km_2013_3_183","DOIUrl":"https://doi.org/10.4149/km_2013_3_183","url":null,"abstract":"In this study, tribological performances of three alloys, 316 L, Ti6Al4V, and CoCrMo, used in manufacturing orthopedic implants, are compared. Wear tests were conducted on a reciprocating wear tester by rubbing an Al2O3 ball. It was found that the wear resistance of the 316 L and CoCrMo alloy was almost 2 and 24 times of the Ti6Al4V alloy, respectively, whose steady state friction coefficient lies between those of the 316 L and CoCrMo alloy. Examinations of wear tracks and contact surfaces of the Al2O3 ball revealed the dominant wear mechanisms as abrasive for CoCrMo and adhesive for 316 L and Ti6Al4V alloy. These observations confirmed that the favorably biocompatible characteristics of Ti6Al4V alloy was not accompanied by a reasonable sliding contact performance. In this respect, surface modification is a necessity for load bearing Ti6Al4V implants to extend their durability in the human body to the levels of 316 L and/or CoCrMo implants. K e y w o r d s: CoCrMo, 316 L, Ti6Al4V, wear","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"44 12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78578557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conventional mechanical joining methods, such as riveting, threaded connection and stamping connection, have obvious shortcomings in heterogeneous sheets joining. A new method of embedded cold joining was put forward, which can easily realize the connection between heterogeneous sheets. The method is suitable for connection of heterogeneous sheets with multi-layers and different thicknesses. This method can also decrease the cost greatly at the same time. Numerical simulation and experimental results indicate that a round hole sample has the maximum embedded depth and flash volume. Meanwhile, the elongation of aluminum sheet in hexagonal hole sample is the smallest. The joint strength of round hole sample increases with increment of the load pressure. Under the same load conditions, the joint strength of hexagonal hole sample is significantly higher than that of round hole and square hole sample. Additionally, the thickness decreased at different points on joint region because of the load pressure increasing. This paper shows an effective way how to realize the heterogeneous sheets connections. K e y w o r d s: heterogeneous sheets, cold press joining, mechanism, reliability
{"title":"Mechanism and reliability of sheets embedded by cold press joining","authors":"F. Li, B. Yuan, Q. Liu, M. Xu","doi":"10.4149/km_2014_2_117","DOIUrl":"https://doi.org/10.4149/km_2014_2_117","url":null,"abstract":"Conventional mechanical joining methods, such as riveting, threaded connection and stamping connection, have obvious shortcomings in heterogeneous sheets joining. A new method of embedded cold joining was put forward, which can easily realize the connection between heterogeneous sheets. The method is suitable for connection of heterogeneous sheets with multi-layers and different thicknesses. This method can also decrease the cost greatly at the same time. Numerical simulation and experimental results indicate that a round hole sample has the maximum embedded depth and flash volume. Meanwhile, the elongation of aluminum sheet in hexagonal hole sample is the smallest. The joint strength of round hole sample increases with increment of the load pressure. Under the same load conditions, the joint strength of hexagonal hole sample is significantly higher than that of round hole and square hole sample. Additionally, the thickness decreased at different points on joint region because of the load pressure increasing. This paper shows an effective way how to realize the heterogeneous sheets connections. K e y w o r d s: heterogeneous sheets, cold press joining, mechanism, reliability","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79388114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of fading and stirring on the performance of the AlTi5B1 and AlTi3C0.15 grain refiners in an Al-Fe alloy","authors":"I. Naglič","doi":"10.4149/km_2010_3_191","DOIUrl":"https://doi.org/10.4149/km_2010_3_191","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77256914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peng Liu, Shikai Li, Yuan-bin Zhang, Hui Luo, Y. Huo
{"title":"A new method to improve tribological properties of titanium by means of Al-Mg intermetallics matrix composite coatings","authors":"Peng Liu, Shikai Li, Yuan-bin Zhang, Hui Luo, Y. Huo","doi":"10.4149/km_2013_2_111","DOIUrl":"https://doi.org/10.4149/km_2013_2_111","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81281252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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