Pure magnesium (Mg) powders together with different amounts of process control agent (PCA) were mechanically milled (MMed) using a vibration ball mill. Stearic acid was used as process control agent (PCA) for the mechanical milling (MM) process. The MMed powders were consolidated into bulk materials by the spark plasma sintering (SPS). Changes in hardness and solid-state reactions of the SPS materials have been examined by hardness measurements and an X-ray diffraction (XRD), respectively. A maximum hardness value of 102 HV obtained in the SPS materials fabricated from MMed 24 h powders with PCA1.50 g at sintering temperature of 823 K for 60 min. Formation of MgO by solid-state reaction was observed for the SPS materials consolidated from MMed 24 h powders with PCA1.00 g and 1.50 g. The amount of MgO formation increased with increasing sintering time. No correlation was observed between MgO formation and hardness. The Vickers hardness of the SPS materials improved by increasing sintering temperature. However, no significant change in hardness and constituent phases was observed with increasing sintering time. Pure Mg of hardness can be improved by MM-SPS process.
{"title":"MM-SPSプロセスで作製した純マグネシウムの硬さに及ぼす焼結保持時間の影響","authors":"Takumi Inomiya, Masahiro Kubota","doi":"10.2464/jilm.73.491","DOIUrl":"https://doi.org/10.2464/jilm.73.491","url":null,"abstract":"Pure magnesium (Mg) powders together with different amounts of process control agent (PCA) were mechanically milled (MMed) using a vibration ball mill. Stearic acid was used as process control agent (PCA) for the mechanical milling (MM) process. The MMed powders were consolidated into bulk materials by the spark plasma sintering (SPS). Changes in hardness and solid-state reactions of the SPS materials have been examined by hardness measurements and an X-ray diffraction (XRD), respectively. A maximum hardness value of 102 HV obtained in the SPS materials fabricated from MMed 24 h powders with PCA1.50 g at sintering temperature of 823 K for 60 min. Formation of MgO by solid-state reaction was observed for the SPS materials consolidated from MMed 24 h powders with PCA1.00 g and 1.50 g. The amount of MgO formation increased with increasing sintering time. No correlation was observed between MgO formation and hardness. The Vickers hardness of the SPS materials improved by increasing sintering temperature. However, no significant change in hardness and constituent phases was observed with increasing sintering time. Pure Mg of hardness can be improved by MM-SPS process.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135766343","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":"ゼロカーボン社会構築におけるアルミニウムとその合金の役割と可能性","authors":"Shin-ichi Kumai","doi":"10.2464/jilm.73.456","DOIUrl":"https://doi.org/10.2464/jilm.73.456","url":null,"abstract":"","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"135 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139339639","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}
Rio Hirano, Shogo Ozaki, Yoshihiro Nagata, Akira Matsushita, Toshio Sakamoto, Kanta Orio, Yasuhiko Okimura, Toshimitsu Okane, Muhammad Khairi Faiz, Makoto Yoshida
Al-Si alloys have lower hot tearing susceptibility (HTS) than other aluminum alloys. However, hot tearing occurs under certain casting conditions. It is known that the Sr addition reduces the HTS because of the enhancement of crack-healing. Meanwhile, an influence of Sr addition on the tensile strength, ductility, and viscous properties during eutectic solidification has not yet been clarified. In this study, we investigated the influence of Sr addition on these properties during eutectic solidification. The tensile tests during eutectic solidification were conducted for Al-2Si and Al-2Si-Sr alloys. The results show that the Sr addition did not affect the viscous properties. On the other hand, the tensile strength and elongation during the latter half of eutectic solidification increased by Sr addition. Consequently, the HTS reduction by Sr addition should be attributed to the improvement of ductility. It was suggested that the increase in the elongation by Sr addition should result from the decrease in the tensile stress, which affects the opening and propagation of hot tearing, due to the increase in porosity near the crack.
{"title":"Influence of Sr on mechanical properties of Al-2%Si alloys during eutectic solidification","authors":"Rio Hirano, Shogo Ozaki, Yoshihiro Nagata, Akira Matsushita, Toshio Sakamoto, Kanta Orio, Yasuhiko Okimura, Toshimitsu Okane, Muhammad Khairi Faiz, Makoto Yoshida","doi":"10.2464/jilm.73.447a","DOIUrl":"https://doi.org/10.2464/jilm.73.447a","url":null,"abstract":"Al-Si alloys have lower hot tearing susceptibility (HTS) than other aluminum alloys. However, hot tearing occurs under certain casting conditions. It is known that the Sr addition reduces the HTS because of the enhancement of crack-healing. Meanwhile, an influence of Sr addition on the tensile strength, ductility, and viscous properties during eutectic solidification has not yet been clarified. In this study, we investigated the influence of Sr addition on these properties during eutectic solidification. The tensile tests during eutectic solidification were conducted for Al-2Si and Al-2Si-Sr alloys. The results show that the Sr addition did not affect the viscous properties. On the other hand, the tensile strength and elongation during the latter half of eutectic solidification increased by Sr addition. Consequently, the HTS reduction by Sr addition should be attributed to the improvement of ductility. It was suggested that the increase in the elongation by Sr addition should result from the decrease in the tensile stress, which affects the opening and propagation of hot tearing, due to the increase in porosity near the crack.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135486905","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":"Impurity elements removal technologies by fractional solidification method for recycling aluminum materials","authors":"Yuichiro Murakami, Keiji Shiga, Naoki Omura","doi":"10.2464/jilm.73.481","DOIUrl":"https://doi.org/10.2464/jilm.73.481","url":null,"abstract":"","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"282 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139339768","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":"Detoxification of impurity elements in recycled aluminum alloys using vertical-type high-speed twin-roll casting and remaining problems for upgrade recycling","authors":"Y. Harada, Shin-ichi Kumai","doi":"10.2464/jilm.73.470","DOIUrl":"https://doi.org/10.2464/jilm.73.470","url":null,"abstract":"","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139339563","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 recent times, the use of aluminum alloys in large-scale structures has been widely advocated. In view of the maintenance and administration of these structures, the implementation of a simple repair methodology holds immense significance. It is imperative to clearly elucidate this methodology and its fatigue-life extension effect. In our study, we examined the effect of a simple repair technique using resin on the fatigue life of aluminum alloys featuring simulated cracks. Our findings confirm the following four points: Firstly, the fatigue life of repaired specimens increased by up to 1.8 times. Secondly, the initiation and growth life of cracks were extended in the repaired specimens. Thirdly, the crack growth rate in the specimens was slower, and fourthly, the striation width was smaller in the specimens. These results strongly suggest that the wedge effect of the resin has suppressed fatigue crack initiation and propagation.
{"title":"Effect of simple repair using resin on fatigue life of A6063 aluminum alloy with a simulated crack","authors":"Daisuke Sasaki, Kaishi Naragino, Mochiyuki Yoshitoshi, Toyomitsu Harada, Makoto Nanko, Yuji Kawakami","doi":"10.2464/jilm.73.375","DOIUrl":"https://doi.org/10.2464/jilm.73.375","url":null,"abstract":"In recent times, the use of aluminum alloys in large-scale structures has been widely advocated. In view of the maintenance and administration of these structures, the implementation of a simple repair methodology holds immense significance. It is imperative to clearly elucidate this methodology and its fatigue-life extension effect. In our study, we examined the effect of a simple repair technique using resin on the fatigue life of aluminum alloys featuring simulated cracks. Our findings confirm the following four points: Firstly, the fatigue life of repaired specimens increased by up to 1.8 times. Secondly, the initiation and growth life of cracks were extended in the repaired specimens. Thirdly, the crack growth rate in the specimens was slower, and fourthly, the striation width was smaller in the specimens. These results strongly suggest that the wedge effect of the resin has suppressed fatigue crack initiation and propagation.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135163441","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}
Amalina Aina Kaharudin, Ran Saeki, Mai Takaya, Tadashi Minoda, Tomoyuki Homma
The bendability of extruded Al-4.4Zn-1.4Mg (mass%) alloy flat bars with 1.4 mm thickness having two types of microstructures which are fibrous and recrystallized is evaluated by a Verband der Automobilindustrie (VDA) bending test without pre-strain. The recrystallized specimen has better bendability than the fibrous one. The texture condition nearby the surfaces affects the VDA bendability the most. However, the microvoid formations also contribute in faster cracking phenomena during the load drop of the VDA bending test.
采用VDA (Verband der Automobilindustrie)无预应变弯曲试验，对具有纤维和再结晶两种组织的1.4 mm厚Al-4.4Zn-1.4Mg(质量%)合金挤压扁棒的可弯曲性进行了评价。再结晶试样比纤维试样具有更好的弯曲性能。表面附近的织构条件对VDA的可弯曲性影响最大。然而，在VDA弯曲试验的载荷下降过程中，微孔隙的形成也导致了更快的开裂现象。
{"title":"Influence of initial extruded microstructures of Al-4.4Zn-1.4Mg alloy flat bar on VDA bendability","authors":"Amalina Aina Kaharudin, Ran Saeki, Mai Takaya, Tadashi Minoda, Tomoyuki Homma","doi":"10.2464/jilm.73.382","DOIUrl":"https://doi.org/10.2464/jilm.73.382","url":null,"abstract":"The bendability of extruded Al-4.4Zn-1.4Mg (mass%) alloy flat bars with 1.4 mm thickness having two types of microstructures which are fibrous and recrystallized is evaluated by a Verband der Automobilindustrie (VDA) bending test without pre-strain. The recrystallized specimen has better bendability than the fibrous one. The texture condition nearby the surfaces affects the VDA bendability the most. However, the microvoid formations also contribute in faster cracking phenomena during the load drop of the VDA bending test.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135163439","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, the effects of the roll load and superheating on the appearance of surface defects in Al-Mg and Al-Si alloy strips cast using a high-speed twin-roll caster were investigated. The band zone that existed in the center of the thickness direction was investigated. The alloy compositions were Al-4.8%Mg and Al-Si with Si contents of 1, 2, 3 and 11%. The diameter and width of the copper roll in the twin-roll caster were 300 and 50 mm, respectively. The superheating temperature of the molten metal was 5 and 50°C, and the roll load was varied from 2 to 88 N/mm. A roll speed of 30 m/min was utilized. The existence of surface cracks was investigated by penetrant inspection and bending test. The amount of surface cracking in the Al-Mg alloy was affected by the roll load, and the number of surface cracks decreased with decreasing roll load. Surface cracks occurred more easily in the Al-4.8%Mg alloy than in the Al-Si alloys. The degree of cracking could not be reduced by cold-rolling. In the Al-Si alloys, the ripple marks were affected by the Si content and the roll load. In the Al-3%Si alloy, ripple marks were produced, and worsened as the roll load increased. A specimen for observation of the microstructure near the roll bite was obtained by performing a roll-stop during casting, and observed using Weck’ s reagent. A band zone was found to exist. The band zone in Al-Si consisted of globular crystals, and that in Al-Mg consisted of equiaxed dendrites and Mg-richareas.
{"title":"Effect of casting conditions on surface defect and segregation of strips cast by a high-speed twin-roll caster","authors":"Kazuki Yamazaki, Toshio Haga","doi":"10.2464/jilm.73.393","DOIUrl":"https://doi.org/10.2464/jilm.73.393","url":null,"abstract":"In this study, the effects of the roll load and superheating on the appearance of surface defects in Al-Mg and Al-Si alloy strips cast using a high-speed twin-roll caster were investigated. The band zone that existed in the center of the thickness direction was investigated. The alloy compositions were Al-4.8%Mg and Al-Si with Si contents of 1, 2, 3 and 11%. The diameter and width of the copper roll in the twin-roll caster were 300 and 50 mm, respectively. The superheating temperature of the molten metal was 5 and 50°C, and the roll load was varied from 2 to 88 N/mm. A roll speed of 30 m/min was utilized. The existence of surface cracks was investigated by penetrant inspection and bending test. The amount of surface cracking in the Al-Mg alloy was affected by the roll load, and the number of surface cracks decreased with decreasing roll load. Surface cracks occurred more easily in the Al-4.8%Mg alloy than in the Al-Si alloys. The degree of cracking could not be reduced by cold-rolling. In the Al-Si alloys, the ripple marks were affected by the Si content and the roll load. In the Al-3%Si alloy, ripple marks were produced, and worsened as the roll load increased. A specimen for observation of the microstructure near the roll bite was obtained by performing a roll-stop during casting, and observed using Weck’ s reagent. A band zone was found to exist. The band zone in Al-Si consisted of globular crystals, and that in Al-Mg consisted of equiaxed dendrites and Mg-richareas.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135163440","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}
A model experiment for in-line hot rolling was proposed, and its effectiveness in reducing surface cracking and improving the mechanical properties of cast strips of AC7A Al-Mg alloy was investigated. The strips were cast using an unequal-diameter twin-roll caster at 60 m/min. The strips had a width of 100 mm, and were immediately cut to a length of 200 mm and hot rolled at temperatures of 300, 350, 400, 450 and 500°C. The temperature of the strip surface was measured using a K-type thermocouple. The center area in the width direction of the strips was hot rolled. The thickness of the as-cast strips was 2 mm, and the width of the rolled region was 20 mm. The roll diameter was 70 mm, and the rolling speed was 15 m/min. The thickness reduction caused by hot rolling ranged from 19 to 42%. Surface cracking was reduced by the in-line hot rolling process. The hot-rolled strips were cold rolled down to a thickness of 0.5 mm and then annealed, and tensile tests were conducted. The in-line hot rolling process induced shear deformation of the microstructure. The most appropriate conditions for in-line hot rolling of AC7A were a thickness reduction of 27% and a temperature of 350°C, judging from the tensile strength and elongation results.
{"title":"異径双ロールキャスターで鋳造したAl-Mg合金板のインライン熱間圧延","authors":"Toshio Haga, Masataka Furukawa","doi":"10.2464/jilm.73.389","DOIUrl":"https://doi.org/10.2464/jilm.73.389","url":null,"abstract":"A model experiment for in-line hot rolling was proposed, and its effectiveness in reducing surface cracking and improving the mechanical properties of cast strips of AC7A Al-Mg alloy was investigated. The strips were cast using an unequal-diameter twin-roll caster at 60 m/min. The strips had a width of 100 mm, and were immediately cut to a length of 200 mm and hot rolled at temperatures of 300, 350, 400, 450 and 500°C. The temperature of the strip surface was measured using a K-type thermocouple. The center area in the width direction of the strips was hot rolled. The thickness of the as-cast strips was 2 mm, and the width of the rolled region was 20 mm. The roll diameter was 70 mm, and the rolling speed was 15 m/min. The thickness reduction caused by hot rolling ranged from 19 to 42%. Surface cracking was reduced by the in-line hot rolling process. The hot-rolled strips were cold rolled down to a thickness of 0.5 mm and then annealed, and tensile tests were conducted. The in-line hot rolling process induced shear deformation of the microstructure. The most appropriate conditions for in-line hot rolling of AC7A were a thickness reduction of 27% and a temperature of 350°C, judging from the tensile strength and elongation results.","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135163446","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":"Effect of microstructure on plane bending fatigue properties of frame-retardant magnesium alloy plates and welded joints","authors":"Naobumi Saito","doi":"10.2464/jilm.73.400","DOIUrl":"https://doi.org/10.2464/jilm.73.400","url":null,"abstract":"","PeriodicalId":16292,"journal":{"name":"Journal of Japan Institute of Light Metals","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135165165","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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