{"title":"\"Precipitation behavior prior to hot roll in the cold-rolled Al-Mg and Al-Mg-Zr alloys \"","authors":"Mohammad Salim Kaiser, Hossain M. Mamun al Rashed","doi":"10.31577/km.2022.4.247","DOIUrl":"https://doi.org/10.31577/km.2022.4.247","url":null,"abstract":"","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"52 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75786561","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}
{"title":"Experimental evaluation and FE simulation of phase transformations and tensile stresses in hot forging and controlled cooling","authors":"C. Hocalar, N. Saklakoğlu, S. Demirok","doi":"10.31577/km.2022.4.257","DOIUrl":"https://doi.org/10.31577/km.2022.4.257","url":null,"abstract":"","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"296 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74161052","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}
Renjin J Bright, G. Selvakumar, P. Hariharasakthisudhan, M. Sumathi
This work studies the mechanical and quasi-static compression behaviour of AA6082/Meta-kaolin composites hybridized with nano-silicon nitride (Si 3 N 4 ) particles. Hybridization with nano-Si 3 N 4 particles was intended to improve the ductility of the composites. The composites were manufactured using an ultrasonication-assisted stir casting process. The weight fraction (wt.%) of Metakaolin was maintained as 7.5 wt.%, and the nano-Si 3 N 4 particles were added by varying their wt.% from 0.5 to 2.5 % at the increment of 0.5 %. A premixing technique was adopted to blend the Metakaolin and Si 3 N 4 reinforcements to improve their wettability and dispersion in the matrix. The tensile properties and microhardness of the composites improved with the incorporation of nano-Si 3 N 4 particles up to 1 wt.%. The compressive strength was higher for the AMC with 1.5 wt.% Si 3 N 4 . The workability of hybrid composites was studied by the cold upsetting process where the composites were subjected to quasi-static compression.
{"title":"Influence of nano-Si3N4(P) hybridization on the mechanical and quasi-static compression behaviour of AA6082-Metakaolin composites","authors":"Renjin J Bright, G. Selvakumar, P. Hariharasakthisudhan, M. Sumathi","doi":"10.31577/km.2022.3.191","DOIUrl":"https://doi.org/10.31577/km.2022.3.191","url":null,"abstract":"This work studies the mechanical and quasi-static compression behaviour of AA6082/Meta-kaolin composites hybridized with nano-silicon nitride (Si 3 N 4 ) particles. Hybridization with nano-Si 3 N 4 particles was intended to improve the ductility of the composites. The composites were manufactured using an ultrasonication-assisted stir casting process. The weight fraction (wt.%) of Metakaolin was maintained as 7.5 wt.%, and the nano-Si 3 N 4 particles were added by varying their wt.% from 0.5 to 2.5 % at the increment of 0.5 %. A premixing technique was adopted to blend the Metakaolin and Si 3 N 4 reinforcements to improve their wettability and dispersion in the matrix. The tensile properties and microhardness of the composites improved with the incorporation of nano-Si 3 N 4 particles up to 1 wt.%. The compressive strength was higher for the AMC with 1.5 wt.% Si 3 N 4 . The workability of hybrid composites was studied by the cold upsetting process where the composites were subjected to quasi-static compression.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"35 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87959619","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 study, a lightweight Al 24 . 2 Si 3 . 25 Cu 24 . 2 Ni 24 . 2 Ti 24 . 2 high-entropy alloy was developed by sonication blending of the pure elements followed by the high-temperature sintering in the nitrogen gas environment. Microstructural characterization of the sintered alloy showed a fair dispersion of the elemental particles in the matrix during the blending process and the absorption of nitrogen, which led to the formation of multiple intermetallic compounds, including the nitrides, during the sintering process. Mechanical characterization of the sintered alloy revealed significantly high microhardness values with relatively lower compressive strength in Al 24 . 2 Si 3 . 25 Cu 24 . 2 Ni 24 . 2 Ti 24 . 2 alloy.
在这项研究中，一个轻量级的al24。2 Si 3。25 Cu 24。2 . Ni 24。2 Ti 24。采用纯元素超声共混，再在氮气环境下高温烧结的方法制备了高熵合金。烧结合金的显微组织表征表明，在共混过程中，元素颗粒在基体中均匀分散，氮的吸收导致烧结过程中形成包括氮化物在内的多种金属间化合物。烧结合金的力学性能表明，al24的显微硬度值较高，而抗压强度相对较低。2 Si 3。25 Cu 24。2 . Ni 24。2 Ti 24。2合金。
{"title":"\"Al24.2Si3.25Cu24.2Ni24.2Ti24.2 high-entropy intermetallic alloy: Effect of nitrogen environment sintered microstructure and mechanical properties \"","authors":"S. Hassan, G. Nadhreen","doi":"10.31577/km.2022.3.163","DOIUrl":"https://doi.org/10.31577/km.2022.3.163","url":null,"abstract":"In this study, a lightweight Al 24 . 2 Si 3 . 25 Cu 24 . 2 Ni 24 . 2 Ti 24 . 2 high-entropy alloy was developed by sonication blending of the pure elements followed by the high-temperature sintering in the nitrogen gas environment. Microstructural characterization of the sintered alloy showed a fair dispersion of the elemental particles in the matrix during the blending process and the absorption of nitrogen, which led to the formation of multiple intermetallic compounds, including the nitrides, during the sintering process. Mechanical characterization of the sintered alloy revealed significantly high microhardness values with relatively lower compressive strength in Al 24 . 2 Si 3 . 25 Cu 24 . 2 Ni 24 . 2 Ti 24 . 2 alloy.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86768580","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}
Aluminum alloys are extensively finding applications in many industries, including automotive and aerospace, because of their lightweight. This research produced a novel aluminum alloy using a stir squeeze casting technique. Sustainability analysis of three competing processes to produce the alloy was carried out using Analytical Hierarchy Process (AHP) method. Scrap aluminum alloy wheels from cars were used as the matrix material. High entropy alloy (HEA) was used as the alloying element, with a total weight percentage of 2.6 %. Hardness, tensile and compressive strength tests were conducted for the developed alloy. An optical microscope, SEM, and XRD were used to analyze the microstructure. The produced alloy was heat-treated, and then mechanical properties and microstructure were compared before and after heat treatment. The results showed a significant improvement in hardness and compressive strength after heat treatment. This improvement is mainly attributed to the Si particle precipitation that occurred during the aging process.
{"title":"Development of a sustainable novel aluminum alloy from scrap car wheels through a stir-squeeze casting process","authors":"Alaa Abdulhady Jaber, P. Krishnan","doi":"10.31577/km.2022.3.151","DOIUrl":"https://doi.org/10.31577/km.2022.3.151","url":null,"abstract":"Aluminum alloys are extensively finding applications in many industries, including automotive and aerospace, because of their lightweight. This research produced a novel aluminum alloy using a stir squeeze casting technique. Sustainability analysis of three competing processes to produce the alloy was carried out using Analytical Hierarchy Process (AHP) method. Scrap aluminum alloy wheels from cars were used as the matrix material. High entropy alloy (HEA) was used as the alloying element, with a total weight percentage of 2.6 %. Hardness, tensile and compressive strength tests were conducted for the developed alloy. An optical microscope, SEM, and XRD were used to analyze the microstructure. The produced alloy was heat-treated, and then mechanical properties and microstructure were compared before and after heat treatment. The results showed a significant improvement in hardness and compressive strength after heat treatment. This improvement is mainly attributed to the Si particle precipitation that occurred during the aging process.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"25 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87500742","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}
ERNiCrFe-7A filler metal is widely used for welding Inconel 690 alloy, which is often considered for fabricating key components such as reactor pressure vessel and steam generator of nuclear island main equipment. In this work, ERNiCrFe-7A deposited metal was prepared by cold wire and hot wire GTAW process separately. The microstructure and mechanism of precipitation of deposited metal were studied by OM, XRD, SEM, and TEM. Results show that both cold wire and hot wire GTAW can get good quality of ERNiCrFe-7A deposited metal. The matrix of deposited metal is γ -austenite. The microstructure of deposited metal has a cellular dendritic characteristic. The intragranular precipitates are MX phases (M = Nb and Ti, X = C and/or N), and the intergranular precipitates are Cr-rich M 23 C 6 phases. The heat input of cold wire GTAW is higher than that of hot wire GTAW, the columnar grains by cold wire GTAW are wider than those of hot wire GTAW, and the number of MX and M 23 C 6 phases by cold wire GTAW is more than that by hot wire GTAW.
ERNiCrFe-7A钎料广泛用于焊接铬镍铁合金，常被考虑用于制造核岛主设备的反应堆压力容器、蒸汽发生器等关键部件。本文采用冷丝法和热丝法分别制备了ERNiCrFe-7A沉积金属。采用OM、XRD、SEM、TEM等方法研究了沉积金属的微观结构和析出机理。结果表明:冷丝和热丝GTAW均可获得较好的ERNiCrFe-7A镀层质量。沉积金属基体为γ -奥氏体。沉积金属的微观结构具有细胞状枝晶特征。晶内析出相为MX相(M = Nb和Ti, X = C和/或N)，晶间析出相为富cr的m23c6相。冷丝GTAW的热输入量高于热丝GTAW，冷丝GTAW的柱状晶粒比热丝GTAW宽，冷丝GTAW的MX相和m23c6相数量多于热丝GTAW。
{"title":"Comparison of the microstructure of ERNiCrFe-7A deposited metal by cold wire GTAW and hot wire GTAW","authors":"H. Zhu, Kun Liu, Xiangping Xu, J. Zou","doi":"10.31577/km.2022.3.181","DOIUrl":"https://doi.org/10.31577/km.2022.3.181","url":null,"abstract":"ERNiCrFe-7A filler metal is widely used for welding Inconel 690 alloy, which is often considered for fabricating key components such as reactor pressure vessel and steam generator of nuclear island main equipment. In this work, ERNiCrFe-7A deposited metal was prepared by cold wire and hot wire GTAW process separately. The microstructure and mechanism of precipitation of deposited metal were studied by OM, XRD, SEM, and TEM. Results show that both cold wire and hot wire GTAW can get good quality of ERNiCrFe-7A deposited metal. The matrix of deposited metal is γ -austenite. The microstructure of deposited metal has a cellular dendritic characteristic. The intragranular precipitates are MX phases (M = Nb and Ti, X = C and/or N), and the intergranular precipitates are Cr-rich M 23 C 6 phases. The heat input of cold wire GTAW is higher than that of hot wire GTAW, the columnar grains by cold wire GTAW are wider than those of hot wire GTAW, and the number of MX and M 23 C 6 phases by cold wire GTAW is more than that by hot wire GTAW.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"31 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76611259","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 order to improve the accuracy of rapid evaluation of the modification effect of Al-Si alloy in front of the furnace, the relationship between resistivity change and modification level during melt solidification was experimentally studied. A melt resistivity monitoring system was designed for practical application, including a sample cup, sample cup base support, vacuum aspiration unit, constant current power supply, data acquisition module, and computer. The monitoring system was used to monitor the changes in temperature and resistivity parameters during solidification of ZL101A alloy melt treated with different amounts of Sr modifier. It was found that the curve of melt resistivity changes with temperature at the eutectic solidification stage had a plateau, and the resistivity plateau value decreased with the better alloy modification effect. Therefore, a rapid evaluation model was established of the hypoeutectic Al-Si alloy modification effect in front of the furnace based on resistivity change during melt solidification. The experimental results showed that the evaluation of the modification effect of the hypoeutectic Al-Si alloy could be completed within 3 minutes by using the monitoring system and evaluation model designed in this paper. The accuracy of the evaluation of modification level error within ± 0.5 reaches 80 % taking the metallographic observation method as the standard.
{"title":"Experimental study on rapid evaluation of modification effect of hypoeutectic Al-Si alloy based on melt solidification process resistivity monitoring","authors":"Ao Wang, Jianming Dong, Dayong Li","doi":"10.31577/km.2022.3.139","DOIUrl":"https://doi.org/10.31577/km.2022.3.139","url":null,"abstract":"In order to improve the accuracy of rapid evaluation of the modification effect of Al-Si alloy in front of the furnace, the relationship between resistivity change and modification level during melt solidification was experimentally studied. A melt resistivity monitoring system was designed for practical application, including a sample cup, sample cup base support, vacuum aspiration unit, constant current power supply, data acquisition module, and computer. The monitoring system was used to monitor the changes in temperature and resistivity parameters during solidification of ZL101A alloy melt treated with different amounts of Sr modifier. It was found that the curve of melt resistivity changes with temperature at the eutectic solidification stage had a plateau, and the resistivity plateau value decreased with the better alloy modification effect. Therefore, a rapid evaluation model was established of the hypoeutectic Al-Si alloy modification effect in front of the furnace based on resistivity change during melt solidification. The experimental results showed that the evaluation of the modification effect of the hypoeutectic Al-Si alloy could be completed within 3 minutes by using the monitoring system and evaluation model designed in this paper. The accuracy of the evaluation of modification level error within ± 0.5 reaches 80 % taking the metallographic observation method as the standard.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"24 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76737170","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}
Melika Ozer, S. Aydogan, A. Ozer, Hanifi Cinic, E. Ayas
Al-Si compacts and Al-Si/B 4 C composites were fabricated by conventional cold pressing + sintering and spark plasma sintering techniques. The effects of powder metallurgy techniques on density, microstructural properties, hardness, and transverse rupture strength were investi-gated. The advantages of spark plasma sintering, which is one of the fast sintering techniques, over conventional sintering were discussed. Green densities and sintered densities were found to decrease with increasing B 4 C addition. The relative density values of the samples produced with spark plasma sintering are over 96 %. B 4 C particles were clustered at the grain boundaries of the master alloy and/or in the intergranular pores. An increase of approximately 40 % was determined in the hardness values of the spark plasma sintering samples compared to the cold pressing+sintering samples. Transverse rupture strength was increased in spark plasma sintering samples containing 5 and 10 wt.% B 4 C.
{"title":"\"Influence of spark plasma sintering and conventional sintering on microstructure and mechanical properties of hypereutectic Al-Si alloy and hypereutectic Al-Si/B4C composites \"","authors":"Melika Ozer, S. Aydogan, A. Ozer, Hanifi Cinic, E. Ayas","doi":"10.31577/km.2022.3.171","DOIUrl":"https://doi.org/10.31577/km.2022.3.171","url":null,"abstract":"Al-Si compacts and Al-Si/B 4 C composites were fabricated by conventional cold pressing + sintering and spark plasma sintering techniques. The effects of powder metallurgy techniques on density, microstructural properties, hardness, and transverse rupture strength were investi-gated. The advantages of spark plasma sintering, which is one of the fast sintering techniques, over conventional sintering were discussed. Green densities and sintered densities were found to decrease with increasing B 4 C addition. The relative density values of the samples produced with spark plasma sintering are over 96 %. B 4 C particles were clustered at the grain boundaries of the master alloy and/or in the intergranular pores. An increase of approximately 40 % was determined in the hardness values of the spark plasma sintering samples compared to the cold pressing+sintering samples. Transverse rupture strength was increased in spark plasma sintering samples containing 5 and 10 wt.% B 4 C.","PeriodicalId":49937,"journal":{"name":"Kovove Materialy-Metallic Materials","volume":"64 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89903408","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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