Pub Date : 2023-01-03DOI: 10.1080/00325899.2022.2163553
C. Ravikanth Reddy, K. Satya Prasad, B. Srinivasarao
ABSTRACT The hexagonal close-packed structure renders magnesium weak at room and high temperatures for structural applications despite its low density. Inducing thermally stable and coherent second phases would enhance/retain the strength of Mg-based alloys even at high temperatures. This paper aims to develop a high-strength Mg-based nanocomposite. A master alloy composed of Ni and Gd was cast and the composition of Mg97.56Ni1.22Gd1.22 (at.-%) was prepared using ball milling for 150 h. XRD plots of the as-milled powder having nano-size crystallites confirm the partial dissolution of the master alloy. Consolidation through sintering with 5, 7 and 9 h of exposure at 550°C and extrusion at 500°C resulted in the formation of Mg5Gd, Mg2Ni, Gd2O3 and MgO phases. The extruded samples possessed a high strength of 804 MPa, which can be attributed to ultra-fine grains and dispersoid strengthening by homogeneously distributed second-phase particles in the 100–200 nm range.
{"title":"Microstructure and mechanical properties of Mg–Ni–Gd alloy synthesised by powder metallurgy","authors":"C. Ravikanth Reddy, K. Satya Prasad, B. Srinivasarao","doi":"10.1080/00325899.2022.2163553","DOIUrl":"https://doi.org/10.1080/00325899.2022.2163553","url":null,"abstract":"ABSTRACT\u0000 The hexagonal close-packed structure renders magnesium weak at room and high temperatures for structural applications despite its low density. Inducing thermally stable and coherent second phases would enhance/retain the strength of Mg-based alloys even at high temperatures. This paper aims to develop a high-strength Mg-based nanocomposite. A master alloy composed of Ni and Gd was cast and the composition of Mg97.56Ni1.22Gd1.22 (at.-%) was prepared using ball milling for 150 h. XRD plots of the as-milled powder having nano-size crystallites confirm the partial dissolution of the master alloy. Consolidation through sintering with 5, 7 and 9 h of exposure at 550°C and extrusion at 500°C resulted in the formation of Mg5Gd, Mg2Ni, Gd2O3 and MgO phases. The extruded samples possessed a high strength of 804 MPa, which can be attributed to ultra-fine grains and dispersoid strengthening by homogeneously distributed second-phase particles in the 100–200 nm range.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"270 - 277"},"PeriodicalIF":1.4,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43305493","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}
Pub Date : 2023-01-01DOI: 10.1080/00325899.2023.2167630
T. Weissgärber, H. Danninger
On 26th January 2023, we commemorate the 100th birthday of Werner Schatt (1923-2009), one of the most eminent persons of powder metallurgy in the twentieth century and a pioneer in the science of sintering. Werner Schatt was born on 26th January 1923, in Friedrichroda in the forest of Thuringia, also known as ‘the green heart of Germany’. Although he lived in Dresden for more than 40 years of his life, he has always emphasised that he was a Thuringian and not a Saxonian. In his youth, Werner Schatt, who was born into a craftsman’s family, suffered from the consequences of World War I, such as inflation and the world economic crisis. He therefore grew up with a deeply engrained work ethic and sense of duty. He finished his high school education in Gotha in 1940, immediately followed by labour service and military service, which after having been trained as an officer he had to do at the Eastern Front. In 1944 he became a prisoner of war in the Soviet Union, from which he returned only in 1949, the conditions of captivity permanently affecting his health. After returning to Germany, at first he had to work in a foundry, where he deburred the cast components by hand, with hammer and chisel. In 1950, now 27 years old, he started his university studies of mechanical engineering at the Technical University of Dresden. He was one of the oldest students in his class but immediately was recognised by his mates as the most able student. In 1954, the eager ‘young’ man, motivated by a hunger for science, finished his diploma in the area of materials science. Professor Friedrich Eisenkolb, the renowned powder metallurgist, was the director of the Scientific Research Institute of Special Metallic Materials in Dresden at that time. Under his supervision, Werner Schatt did his Ph.D. on Al2O3-Cr composites. After his doctoral studies (1959), Schatt became the head of the metallurgy section in the Deutsches Amt für Materialund Warenprüfung (Materials and Product Testing Establishment, DAMW) in Magdeburg. In 1963, he was awarded a professorship in materials technology at the neighbouring institute founded and directed by Ernst Schiebold. After Schiebold’s death, he was assigned the deputy directorship of the institute; his directorial and management duties were combined with extensive teaching obligations. Werner Schatt finished his habilitation (venia docendi) at THMagdeburg with a thesis on ‘metallographic methods for the determination of the orientation of single crystals and polycrystals’. In 1966, he was appointed as the successor to Professor Friedrich Eisenkolb at the Institute for Materials Science at TH Dresden. In 1968, he received and accepted an official offer as a Full Professor of materials science. He headed the Research Area of the same name and was head of the research area materials technology until he was raised to Emeritus status in 1988 [1]. After commencing his appointment in Dresden, Schatt concentrated his research on powder metallurgy. He s
{"title":"On the 100th birthday of Prof. Dr.-Ing. habil. Dr.-Ing. E.h. Werner Schatt","authors":"T. Weissgärber, H. Danninger","doi":"10.1080/00325899.2023.2167630","DOIUrl":"https://doi.org/10.1080/00325899.2023.2167630","url":null,"abstract":"On 26th January 2023, we commemorate the 100th birthday of Werner Schatt (1923-2009), one of the most eminent persons of powder metallurgy in the twentieth century and a pioneer in the science of sintering. Werner Schatt was born on 26th January 1923, in Friedrichroda in the forest of Thuringia, also known as ‘the green heart of Germany’. Although he lived in Dresden for more than 40 years of his life, he has always emphasised that he was a Thuringian and not a Saxonian. In his youth, Werner Schatt, who was born into a craftsman’s family, suffered from the consequences of World War I, such as inflation and the world economic crisis. He therefore grew up with a deeply engrained work ethic and sense of duty. He finished his high school education in Gotha in 1940, immediately followed by labour service and military service, which after having been trained as an officer he had to do at the Eastern Front. In 1944 he became a prisoner of war in the Soviet Union, from which he returned only in 1949, the conditions of captivity permanently affecting his health. After returning to Germany, at first he had to work in a foundry, where he deburred the cast components by hand, with hammer and chisel. In 1950, now 27 years old, he started his university studies of mechanical engineering at the Technical University of Dresden. He was one of the oldest students in his class but immediately was recognised by his mates as the most able student. In 1954, the eager ‘young’ man, motivated by a hunger for science, finished his diploma in the area of materials science. Professor Friedrich Eisenkolb, the renowned powder metallurgist, was the director of the Scientific Research Institute of Special Metallic Materials in Dresden at that time. Under his supervision, Werner Schatt did his Ph.D. on Al2O3-Cr composites. After his doctoral studies (1959), Schatt became the head of the metallurgy section in the Deutsches Amt für Materialund Warenprüfung (Materials and Product Testing Establishment, DAMW) in Magdeburg. In 1963, he was awarded a professorship in materials technology at the neighbouring institute founded and directed by Ernst Schiebold. After Schiebold’s death, he was assigned the deputy directorship of the institute; his directorial and management duties were combined with extensive teaching obligations. Werner Schatt finished his habilitation (venia docendi) at THMagdeburg with a thesis on ‘metallographic methods for the determination of the orientation of single crystals and polycrystals’. In 1966, he was appointed as the successor to Professor Friedrich Eisenkolb at the Institute for Materials Science at TH Dresden. In 1968, he received and accepted an official offer as a Full Professor of materials science. He headed the Research Area of the same name and was head of the research area materials technology until he was raised to Emeritus status in 1988 [1]. After commencing his appointment in Dresden, Schatt concentrated his research on powder metallurgy. He s","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"1 - 2"},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41927023","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}
Pub Date : 2022-12-29DOI: 10.1080/00325899.2022.2162204
I. I. López-López, J. J. Morales, J. Solis, J. Lemus, J. A. Verduzco
ABSTRACT This work reports the effect of micro strain of soft magnetic materials obtained by low-energy ball milling. It has been observed that the low energy of the ball milling changes the magnetic domain size, increasing magnetisation, remanence and magnetic permeability of the milled powders as ferromagnetic particles. It is due to the increase of linear defects and the increase of lattice strain. The magnetisation M S increases up to 70% by the accumulation of crystalline defects, although M S decreases with the reduction of particle size, due to the connections of voids between the lines of magnetisation across the crystalline defects obtained by milling. This response is produced by the cold working through the ball milling.
{"title":"Effect of low energy milling processes on the magnetic properties of Fe–Ni–Co soft magnetic materials","authors":"I. I. López-López, J. J. Morales, J. Solis, J. Lemus, J. A. Verduzco","doi":"10.1080/00325899.2022.2162204","DOIUrl":"https://doi.org/10.1080/00325899.2022.2162204","url":null,"abstract":"ABSTRACT This work reports the effect of micro strain of soft magnetic materials obtained by low-energy ball milling. It has been observed that the low energy of the ball milling changes the magnetic domain size, increasing magnetisation, remanence and magnetic permeability of the milled powders as ferromagnetic particles. It is due to the increase of linear defects and the increase of lattice strain. The magnetisation M S increases up to 70% by the accumulation of crystalline defects, although M S decreases with the reduction of particle size, due to the connections of voids between the lines of magnetisation across the crystalline defects obtained by milling. This response is produced by the cold working through the ball milling.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"263 - 269"},"PeriodicalIF":1.4,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46276144","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}
Pub Date : 2022-11-17DOI: 10.1080/00325899.2022.2146889
Tobias Koch, Hans Joachim Particke
Peter Vervoort has worked in the powder metallurgy industry for many decades, in various companies. For the last nine years, he was working at the furnace manufacturer ONEJOON GmbH (formerly Eisenmann Thermal Solutions). As Vice President, he was responsible for the business area Global Technology and played a major role in the development and establishment of ONEJOON’s Test Center. Peter Vervoort was always excited about his profession. His excitement for technological developments and complex challenges not only inspired his co-workers, but also colleagues and customers worldwide. His vast expertise, creativeness and ability to view the customer’s challenges from their perspective and embrace their goals have been remarkable. He did this with the knowledge of an academically trained analyst and developer who picked up the gauge himself from time to time and set his hands on the furnace. Mr Vervoort devoted his interest to the invention and advancement of procedures, plant concepts as well as innovative applications and technologies. He played a leading role in the successful entry of ONEJOON into the Battery & Powder Materials market. Moreover, Peter Vervoort was a renowned expert in the field of powder metallurgy and an active member of national and international boards. He was a much soughtafter speaker at conferences and author of articles and books. The technological education of young people was a matter close to his heart. He successfully strengthened co-operations with universities. Within his company, both students at the Test Center and colleagues benefited from his didactic talent through personal discussions or ONEJOON Campus lectures. His team could always approach him and he was a mentor who communicated on eye level. Peter was also a regular member of the Technical Committee, session chair and speaker in EPMA congresses, and lecturer in many other EPMA events, including several Powder Metallurgy Summer Schools – the last time in June 2022 but also in many earlier editions – where he covered the fields of sintering practice and furnace technology, transferring his enthusiasm for powder metallurgy to the next generation. With his exemplary engagement, distinct sense of responsibility and charisma, he gained lasting reputation within and outside his company. Peter will be honourably remembered by all who had the privilege to know him and work with him.
Peter Vervoort在多家公司的粉末冶金行业工作了几十年。在过去的九年里，他一直在熔炉制造商ONEJOON GmbH（前身为艾森曼热解决方案公司）工作。作为副总裁，他负责全球技术业务领域，并在ONEOON测试中心的开发和建立中发挥了重要作用。Peter Vervoort总是对自己的职业感到兴奋。他对技术发展和复杂挑战的兴奋不仅激励了他的同事，也激励了世界各地的同事和客户。他丰富的专业知识、创造力以及从客户的角度看待客户挑战并实现目标的能力都非常出色。他是在一位受过学术培训的分析师和开发人员的知识下完成这项工作的，他自己不时拿起仪表，把手放在炉子上。Vervoort先生致力于程序、植物概念以及创新应用和技术的发明和进步。他在ONEOON成功进入电池和粉末材料市场的过程中发挥了主导作用。此外，Peter Vervoort是粉末冶金领域的著名专家，也是国家和国际委员会的积极成员。他在会议上是一位非常受欢迎的演讲者，也是文章和书籍的作者。对年轻人的技术教育是他非常关心的问题。他成功地加强了与大学的合作。在他的公司内，测试中心的学生和同事都通过个人讨论或ONEJOON校园讲座受益于他的教学天赋。他的团队总是可以接近他，他是一位用眼睛交流的导师。Peter还是技术委员会的固定成员、EPMA大会的会议主席和发言人，并在许多其他EPMA活动中担任讲师，包括几所粉末冶金暑期学校——上一次是在2022年6月，但也在许多早期版本中——他在会上涵盖了烧结实践和熔炉技术领域，将他对粉末冶金的热情传递给下一代。凭借他堪称楷模的敬业精神、独特的责任感和魅力，他在公司内外赢得了持久的声誉。所有有幸认识彼得并与他共事的人都将永远怀念他。
{"title":"ONEJOON GmbH and the Powder Metallurgy Community mourn the loss of our colleague Peter Vervoort","authors":"Tobias Koch, Hans Joachim Particke","doi":"10.1080/00325899.2022.2146889","DOIUrl":"https://doi.org/10.1080/00325899.2022.2146889","url":null,"abstract":"Peter Vervoort has worked in the powder metallurgy industry for many decades, in various companies. For the last nine years, he was working at the furnace manufacturer ONEJOON GmbH (formerly Eisenmann Thermal Solutions). As Vice President, he was responsible for the business area Global Technology and played a major role in the development and establishment of ONEJOON’s Test Center. Peter Vervoort was always excited about his profession. His excitement for technological developments and complex challenges not only inspired his co-workers, but also colleagues and customers worldwide. His vast expertise, creativeness and ability to view the customer’s challenges from their perspective and embrace their goals have been remarkable. He did this with the knowledge of an academically trained analyst and developer who picked up the gauge himself from time to time and set his hands on the furnace. Mr Vervoort devoted his interest to the invention and advancement of procedures, plant concepts as well as innovative applications and technologies. He played a leading role in the successful entry of ONEJOON into the Battery & Powder Materials market. Moreover, Peter Vervoort was a renowned expert in the field of powder metallurgy and an active member of national and international boards. He was a much soughtafter speaker at conferences and author of articles and books. The technological education of young people was a matter close to his heart. He successfully strengthened co-operations with universities. Within his company, both students at the Test Center and colleagues benefited from his didactic talent through personal discussions or ONEJOON Campus lectures. His team could always approach him and he was a mentor who communicated on eye level. Peter was also a regular member of the Technical Committee, session chair and speaker in EPMA congresses, and lecturer in many other EPMA events, including several Powder Metallurgy Summer Schools – the last time in June 2022 but also in many earlier editions – where he covered the fields of sintering practice and furnace technology, transferring his enthusiasm for powder metallurgy to the next generation. With his exemplary engagement, distinct sense of responsibility and charisma, he gained lasting reputation within and outside his company. Peter will be honourably remembered by all who had the privilege to know him and work with him.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"85 - 85"},"PeriodicalIF":1.4,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45286138","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}
Pub Date : 2022-11-02DOI: 10.1080/00325899.2022.2141095
Yang Zhou, Fang Yang, Cun-guang Chen, Zhimeng Guo
ABSTRACT High oxygen Ti6Al4V alloys are fabricated by vacuum sintering and hot rolling using hydrogenation-dehydrogenation Ti6Al4V powder and ZrO2 powder as raw materials. The complete dissolution of oxygen and zirconium atoms results in an increase in lattice constant and strength. As-rolled Ti64-ZrO2 sample exhibits a bimodal structure with a fine acicular α phase of around 1 μm. Ti64-0.75 ZrO2 alloy with equivalent oxygen content close to 0.6 wt.-% presents a good combination of the high tensile strength (1180.2 MPa) and sufficient elongation (7.3%). Therefore, the critical oxygen content for the ductile-to-brittle transition of powder metallurgy Ti6Al4V alloy can be improved by suitable preparation methods. The formation of a fine β transformation structure may be one of the reasons for maintaining sufficient ductility.
{"title":"Microstructure evolution and mechanical property of powder metallurgy Ti6Al4V alloy with high oxygen concentrations","authors":"Yang Zhou, Fang Yang, Cun-guang Chen, Zhimeng Guo","doi":"10.1080/00325899.2022.2141095","DOIUrl":"https://doi.org/10.1080/00325899.2022.2141095","url":null,"abstract":"ABSTRACT High oxygen Ti6Al4V alloys are fabricated by vacuum sintering and hot rolling using hydrogenation-dehydrogenation Ti6Al4V powder and ZrO2 powder as raw materials. The complete dissolution of oxygen and zirconium atoms results in an increase in lattice constant and strength. As-rolled Ti64-ZrO2 sample exhibits a bimodal structure with a fine acicular α phase of around 1 μm. Ti64-0.75 ZrO2 alloy with equivalent oxygen content close to 0.6 wt.-% presents a good combination of the high tensile strength (1180.2 MPa) and sufficient elongation (7.3%). Therefore, the critical oxygen content for the ductile-to-brittle transition of powder metallurgy Ti6Al4V alloy can be improved by suitable preparation methods. The formation of a fine β transformation structure may be one of the reasons for maintaining sufficient ductility.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"236 - 247"},"PeriodicalIF":1.4,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49307137","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}
Pub Date : 2022-10-28DOI: 10.1080/00325899.2022.2138171
P. Scholzen, A. Rajaei, J. Brimmers, B. Hallstedt, T. Bergs, C. Broeckmann
ABSTRACT The powder metallurgical manufacturing of gears offers a promising opportunity in terms of reducing the noise emission and increasing the power density. Sintered gears weigh less than conventional gears and potentially have a better noise-vibration-harshness behaviour, due to the remaining porosity. However, the potential of sintered gears for highly loaded applications is not fully utilised yet. Six variants of surface densified and case-hardened sintered gears from Astaloy Mo85 are tested to analyse the impact of the densification and case hardening depths on both the tooth root and flank load bearing capacities. Experimental investigations including metallography and computer tomography are carried out to characterise the microstructure. Furthermore, a simulation model is developed to quantitatively describe the residual stress and hardness profiles after the heat treatment. The load bearing capacity was improved by increasing the densification and case hardening depths, where the effect of the case hardening was identified to be predominant.
{"title":"Influence of heat treatment and densification on the load capacity of sintered gears","authors":"P. Scholzen, A. Rajaei, J. Brimmers, B. Hallstedt, T. Bergs, C. Broeckmann","doi":"10.1080/00325899.2022.2138171","DOIUrl":"https://doi.org/10.1080/00325899.2022.2138171","url":null,"abstract":"ABSTRACT\u0000 The powder metallurgical manufacturing of gears offers a promising opportunity in terms of reducing the noise emission and increasing the power density. Sintered gears weigh less than conventional gears and potentially have a better noise-vibration-harshness behaviour, due to the remaining porosity. However, the potential of sintered gears for highly loaded applications is not fully utilised yet. Six variants of surface densified and case-hardened sintered gears from Astaloy Mo85 are tested to analyse the impact of the densification and case hardening depths on both the tooth root and flank load bearing capacities. Experimental investigations including metallography and computer tomography are carried out to characterise the microstructure. Furthermore, a simulation model is developed to quantitatively describe the residual stress and hardness profiles after the heat treatment. The load bearing capacity was improved by increasing the densification and case hardening depths, where the effect of the case hardening was identified to be predominant.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"86 - 93"},"PeriodicalIF":1.4,"publicationDate":"2022-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45263024","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}
Pub Date : 2022-10-18DOI: 10.1080/00325899.2022.2133357
L. Cordova, C. Sithole, Eric Macía Rodríguez, I. Gibson, M. Campos
ABSTRACT In powder bed fusion laser beam (PBF-LB), powder reusability remains key to keeping cost-effectivity as well as sustainability. In this study, highly sensitive Ti6Al4V ELI powder typically used for medical and aerospace applications is studied. Powder properties of new and reused powders after 10 build cycles subjected to variations such as morphology, particle size distribution (PSD), chemical composition and flowability were analysed. The flow rate using Carney flowmeter increased from 6.8 s to 12 s. Oxygen content slightly increased from 0.11% to 0.12%. The dimensional deviations are measured in six builds of eight samples spread through the build plate. The density of the cubes does not show relevant differences in density (from 99.6% to 99.9%), only the last batch exhibits slightly lower density than the previous builds. Studied properties for the powder and builds are maintained throughout the experiment, demonstrating repeatability of industrial production of metal parts.
{"title":"Impact of powder reusability on batch repeatability of Ti6Al4V ELI for PBF-LB industrial production","authors":"L. Cordova, C. Sithole, Eric Macía Rodríguez, I. Gibson, M. Campos","doi":"10.1080/00325899.2022.2133357","DOIUrl":"https://doi.org/10.1080/00325899.2022.2133357","url":null,"abstract":"ABSTRACT In powder bed fusion laser beam (PBF-LB), powder reusability remains key to keeping cost-effectivity as well as sustainability. In this study, highly sensitive Ti6Al4V ELI powder typically used for medical and aerospace applications is studied. Powder properties of new and reused powders after 10 build cycles subjected to variations such as morphology, particle size distribution (PSD), chemical composition and flowability were analysed. The flow rate using Carney flowmeter increased from 6.8 s to 12 s. Oxygen content slightly increased from 0.11% to 0.12%. The dimensional deviations are measured in six builds of eight samples spread through the build plate. The density of the cubes does not show relevant differences in density (from 99.6% to 99.9%), only the last batch exhibits slightly lower density than the previous builds. Studied properties for the powder and builds are maintained throughout the experiment, demonstrating repeatability of industrial production of metal parts.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"129 - 138"},"PeriodicalIF":1.4,"publicationDate":"2022-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42916621","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}
Pub Date : 2022-10-17DOI: 10.1080/00325899.2022.2134083
W. Hearn, P. Harlin, E. Hryha
ABSTRACT This study focuses on process development and mechanical property evaluation of AISI 4140, 4340 and 8620 low-alloy steel produced by powder bed fusion – laser beam (PBF-LB). Process development found that increasing the build plate preheating temperature to 180°C improved processability, as it mitigated lack of fusion and cold cracking defects. Subsequent mechanical testing found that the low-alloy steels achieved a high ultimate tensile strength (4140:∼1400 MPa, 4340:∼1500 MPa, 8620:∼1100 MPa), impact toughness (4140:∼90–100 J, 4340:∼60–70 J, 8620:∼150–175 J) and elongation (4140:∼14%, 4340:∼14%, 8620:∼14–15%) that met or exceeded the ASTM standards. Mechanical testing also revealed limited directional anisotropy that was attributed to low levels of internal defects (< 0.1%), small grains with weak crystallographic texture and improved tempering due to build plate preheating and post PBF-LB stress relief. This indicates that with adequate process development, low-alloy steels produced by PBF-LB can meet or exceed the performance of conventionally produced alloys.
{"title":"Development of powder bed fusion – laser beam process for AISI 4140, 4340 and 8620 low-alloy steel","authors":"W. Hearn, P. Harlin, E. Hryha","doi":"10.1080/00325899.2022.2134083","DOIUrl":"https://doi.org/10.1080/00325899.2022.2134083","url":null,"abstract":"ABSTRACT This study focuses on process development and mechanical property evaluation of AISI 4140, 4340 and 8620 low-alloy steel produced by powder bed fusion – laser beam (PBF-LB). Process development found that increasing the build plate preheating temperature to 180°C improved processability, as it mitigated lack of fusion and cold cracking defects. Subsequent mechanical testing found that the low-alloy steels achieved a high ultimate tensile strength (4140:∼1400 MPa, 4340:∼1500 MPa, 8620:∼1100 MPa), impact toughness (4140:∼90–100 J, 4340:∼60–70 J, 8620:∼150–175 J) and elongation (4140:∼14%, 4340:∼14%, 8620:∼14–15%) that met or exceeded the ASTM standards. Mechanical testing also revealed limited directional anisotropy that was attributed to low levels of internal defects (< 0.1%), small grains with weak crystallographic texture and improved tempering due to build plate preheating and post PBF-LB stress relief. This indicates that with adequate process development, low-alloy steels produced by PBF-LB can meet or exceed the performance of conventionally produced alloys.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"55 4","pages":"94 - 106"},"PeriodicalIF":1.4,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41305555","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}
Pub Date : 2022-08-30DOI: 10.1080/00325899.2022.2116401
G. Bagliuk, S. Kyryliuk
ABSTRACT Comparative results of numerical simulation of the process of hot forging of porous preforms with an axial hole for two deformation schemes are presented: in a die with a flash groove on the inner surface of the forged workpiece cavity and in a closed die. A significant difference in the nature of the evolution of the distribution of deformations and density over the cross-section of the workpiece for the two considered schemes is noted. It is shown that forging in a die with an open volume provides significantly higher degrees of material deformation during forging compared to closed forging, which should lead to an increase in the quality of the structure and final properties of the forged material.
{"title":"Finite element simulation of different deformation modes for powder hot forging","authors":"G. Bagliuk, S. Kyryliuk","doi":"10.1080/00325899.2022.2116401","DOIUrl":"https://doi.org/10.1080/00325899.2022.2116401","url":null,"abstract":"ABSTRACT Comparative results of numerical simulation of the process of hot forging of porous preforms with an axial hole for two deformation schemes are presented: in a die with a flash groove on the inner surface of the forged workpiece cavity and in a closed die. A significant difference in the nature of the evolution of the distribution of deformations and density over the cross-section of the workpiece for the two considered schemes is noted. It is shown that forging in a die with an open volume provides significantly higher degrees of material deformation during forging compared to closed forging, which should lead to an increase in the quality of the structure and final properties of the forged material.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":"66 1","pages":"176 - 186"},"PeriodicalIF":1.4,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47386876","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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