Pub Date : 2017-01-01DOI: 10.2320/JINSTMET.J2016066
Yasutaka Hashimoto, T. Nishi, H. Ohta
The viscosities of the lead–free solders are important to simulate the process of the manufacturing process. In this article, current status of the viscosity measurements for the lead–free solders are reviewed. In addition, we introduced the current work of the viscosity measurements for the lead–free solders by using the rotational viscometer with concentric cylinder spindle geometry. [doi:10.2320/jinstmet.J2016066]
{"title":"Current Status and Future Plan of the Viscosity Measurement for the Lead-Free Solder","authors":"Yasutaka Hashimoto, T. Nishi, H. Ohta","doi":"10.2320/JINSTMET.J2016066","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2016066","url":null,"abstract":"The viscosities of the lead–free solders are important to simulate the process of the manufacturing process. In this article, current status of the viscosity measurements for the lead–free solders are reviewed. In addition, we introduced the current work of the viscosity measurements for the lead–free solders by using the rotational viscometer with concentric cylinder spindle geometry. [doi:10.2320/jinstmet.J2016066]","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"36 1","pages":"221-225"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88184290","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2016061
T. Abe, K. Hashimoto, M. Shimono
Thermal vacancies in solids have not been treated explicitly in the CALPHAD-type thermodynamic assessments because it was considered that their contributions to the Gibbs energy were limited, even at the melting point. However, the vacancy fraction is necessary for dynamic simulations, such as precipitations and di ff usion processes. In this paper, a procedure is proposed to set parameters in the CALPHAD-type assessments, to reproduce the temperature dependency of thermal vacancies in pure metals and solid solutions.
{"title":"Description of the Thermal Vacancies in the CALPHAD Method","authors":"T. Abe, K. Hashimoto, M. Shimono","doi":"10.2320/JINSTMET.J2016061","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2016061","url":null,"abstract":"Thermal vacancies in solids have not been treated explicitly in the CALPHAD-type thermodynamic assessments because it was considered that their contributions to the Gibbs energy were limited, even at the melting point. However, the vacancy fraction is necessary for dynamic simulations, such as precipitations and di ff usion processes. In this paper, a procedure is proposed to set parameters in the CALPHAD-type assessments, to reproduce the temperature dependency of thermal vacancies in pure metals and solid solutions.","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"36 1","pages":"127-132"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85535585","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2016060
R. Yoshimura, H. Esaka, K. Shinozuka
{"title":"Influence of the Addition of Small Amount of Zn on the Solidification of Sn-Ag Alloys","authors":"R. Yoshimura, H. Esaka, K. Shinozuka","doi":"10.2320/JINSTMET.J2016060","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2016060","url":null,"abstract":"","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"24 1","pages":"257-263"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74574277","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2017001
M. Tsukamoto
The recrystallized textures of 5083 aluminum alloy plates were examined. These plates were cold rolled at total reduction rates of 30, 50 and 85%, followed by annealing. When reduction rate was 30%, recrystallization was not complete and recovered grains remained despite annealing the specimen at 673 K for 10.8 ks in a salt bath. Recrystallized grains were mostly formed through particle stimulated nucleation, while strain induced grain boundary migration was scarcely occurred. The orientations of recrystallized grains were similar to those of the grains obtained after cold rolling. The orientations of recovered grains were returned to those of the grains before cold rolling with annealing. When reduction rate was 50%, the lattice rotations in the grains increased slightly as compared with the specimen that was cold rolled at a reduction rate of 30%. The distribution of the orientation was close to that of a β–fiber composed of copper, brass and S orientations. Several grains with the {142} plane parallel to the rolling direction were observed. On the contrary, the grains with the {111} plane parallel to the rolling direction decreased. When reduction rate was 85%, the image of the microstructure formed after cold rolling could not be obtained using SEM–EBSD. This was because Kikuchi patterns were not clear owing to the formation of dislocation tangles close to the rolling surface. EBSD images could be obtained by annealing the specimen at 673 K for 3 s. It can be considered that dislocation tangles were rearranged and changed into subgrains. The orientations of recrystallized grains close to precipitations were considerably irregular. However, these grains were difficult to grow. The grains with the {142} plane parallel to the rolling direction were more in the specimen cold rolled at a reduction rate of 85% than in the specimen cold rolled at a reduction rate of 50%. It was concluded that the <142>//ND texture was gradually constructed by increasing the total reduction rate for the cold rolling of 5083 aluminum alloy. [doi:10.2320/jinstmet.J2017001]
{"title":"Changes in Recrystallized Texture after Annealing of 5083 Aluminum Alloy Cold Rolled at Increasing Reduction Rate","authors":"M. Tsukamoto","doi":"10.2320/JINSTMET.J2017001","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2017001","url":null,"abstract":"The recrystallized textures of 5083 aluminum alloy plates were examined. These plates were cold rolled at total reduction rates of 30, 50 and 85%, followed by annealing. When reduction rate was 30%, recrystallization was not complete and recovered grains remained despite annealing the specimen at 673 K for 10.8 ks in a salt bath. Recrystallized grains were mostly formed through particle stimulated nucleation, while strain induced grain boundary migration was scarcely occurred. The orientations of recrystallized grains were similar to those of the grains obtained after cold rolling. The orientations of recovered grains were returned to those of the grains before cold rolling with annealing. When reduction rate was 50%, the lattice rotations in the grains increased slightly as compared with the specimen that was cold rolled at a reduction rate of 30%. The distribution of the orientation was close to that of a β–fiber composed of copper, brass and S orientations. Several grains with the {142} plane parallel to the rolling direction were observed. On the contrary, the grains with the {111} plane parallel to the rolling direction decreased. When reduction rate was 85%, the image of the microstructure formed after cold rolling could not be obtained using SEM–EBSD. This was because Kikuchi patterns were not clear owing to the formation of dislocation tangles close to the rolling surface. EBSD images could be obtained by annealing the specimen at 673 K for 3 s. It can be considered that dislocation tangles were rearranged and changed into subgrains. The orientations of recrystallized grains close to precipitations were considerably irregular. However, these grains were difficult to grow. The grains with the {142} plane parallel to the rolling direction were more in the specimen cold rolled at a reduction rate of 85% than in the specimen cold rolled at a reduction rate of 50%. It was concluded that the <142>//ND texture was gradually constructed by increasing the total reduction rate for the cold rolling of 5083 aluminum alloy. [doi:10.2320/jinstmet.J2017001]","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"32 1","pages":"394-402"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80242650","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2016047
Y. Funakawa
The interface–precipitation has been observed as row carbide arrange since 1960's. Whereas the interface–precipitated carbides in steels were NbC, TiC, VC and Cr23C6 in the early stage, composite TiC containing Mo and W has been also become to observe recently. Several kinds of the mechanism of the interface–precipitation have been suggested and ledge mechanism and bowing mechanism which combined interface barging and carbide precipitation are widely accepted since the mechanisms successfully explained a large amount of the experimental results. Fine interface–precipitates in low carbon steel realize high strength steel sheets, plates, bars and rods which are non–quenched and tempered. Especially, in sheet products, in which fine carbides can be easily generated, ferritic steel of 1180 MPa in tensile strength is successfully obtained by dispersing fine carbides with the diameter of several nano–meters. [doi:10.2320/jinstmet.J2016047]
{"title":"Interface Precipitation and Application to Practical Steels","authors":"Y. Funakawa","doi":"10.2320/JINSTMET.J2016047","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2016047","url":null,"abstract":"The interface–precipitation has been observed as row carbide arrange since 1960's. Whereas the interface–precipitated carbides in steels were NbC, TiC, VC and Cr23C6 in the early stage, composite TiC containing Mo and W has been also become to observe recently. Several kinds of the mechanism of the interface–precipitation have been suggested and ledge mechanism and bowing mechanism which combined interface barging and carbide precipitation are widely accepted since the mechanisms successfully explained a large amount of the experimental results. Fine interface–precipitates in low carbon steel realize high strength steel sheets, plates, bars and rods which are non–quenched and tempered. Especially, in sheet products, in which fine carbides can be easily generated, ferritic steel of 1180 MPa in tensile strength is successfully obtained by dispersing fine carbides with the diameter of several nano–meters. [doi:10.2320/jinstmet.J2016047]","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"25 1","pages":"447-457"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79097445","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2017005
A. Sekita, Aira Matsugaki, Ryosuke Ozasa, T. Nakano
Bone tissue has a highly anisotropic microstructure derived from collagen matrix alignment and the crystallographic orientation of apatite. Bone is also a highly vascularized tissue; intraosseous vascularization and bone formation are intimately coupled. Mean -while, the structural relations between intraosseous vascular networks and bone microstructure are as yet unknown, partially due to technical difficulties in visualizing precise intraosseous vasculatures. The aim of this study is to develop a visualization method suitable for the structural analysis of intraosseous vascular networks and to reveal the relations between bone microstructure and the arrangement patterns of intraosseous vasculatures both in intact and metastasized bones. Three - dimensional vascular networks were successfully visualized, and region - dependent arrangement patterns of blood vessels were clarified using fluorescent dye - conjugated lectin. Interestingly, the anisotropic structural correlation between bone matrix and the vascular system in a region specific manner was clarified. In addition, the impaired anisotropic vascular networks in metastasized bone was clarified. The obtained results indicate the molecular interactions between the vascular system and bone tissue as a novel contributor for realiza tion of anisotropic bone matrix construct. ］ （ ）
{"title":"Association between Intraosseous Vasculature and Bone Matrix Anisotropy Analyzed with a Novel Visualization Method","authors":"A. Sekita, Aira Matsugaki, Ryosuke Ozasa, T. Nakano","doi":"10.2320/JINSTMET.J2017005","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2017005","url":null,"abstract":"Bone tissue has a highly anisotropic microstructure derived from collagen matrix alignment and the crystallographic orientation of apatite. Bone is also a highly vascularized tissue; intraosseous vascularization and bone formation are intimately coupled. Mean -while, the structural relations between intraosseous vascular networks and bone microstructure are as yet unknown, partially due to technical difficulties in visualizing precise intraosseous vasculatures. The aim of this study is to develop a visualization method suitable for the structural analysis of intraosseous vascular networks and to reveal the relations between bone microstructure and the arrangement patterns of intraosseous vasculatures both in intact and metastasized bones. Three - dimensional vascular networks were successfully visualized, and region - dependent arrangement patterns of blood vessels were clarified using fluorescent dye - conjugated lectin. Interestingly, the anisotropic structural correlation between bone matrix and the vascular system in a region specific manner was clarified. In addition, the impaired anisotropic vascular networks in metastasized bone was clarified. The obtained results indicate the molecular interactions between the vascular system and bone tissue as a novel contributor for realiza tion of anisotropic bone matrix construct. ］ （ ）","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"1 1","pages":"315-319"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82350943","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 : 2017-01-01DOI: 10.2320/JINSTMET.JAW201703
Y. Kinoshita, M. Morishita, A. Nozaki, Hiroaki Yamamoto
{"title":"Thermodynamic Properties for Nd 2 (MoO 4 ) 3 Formed in the Nuclear Fuel Waste Glasses","authors":"Y. Kinoshita, M. Morishita, A. Nozaki, Hiroaki Yamamoto","doi":"10.2320/JINSTMET.JAW201703","DOIUrl":"https://doi.org/10.2320/JINSTMET.JAW201703","url":null,"abstract":"","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"44 1","pages":"485-493"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90687917","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 : 2017-01-01DOI: 10.2320/jinstmet.jb201705
S. Hayashi, D. Takashima, Norifumi Kochi, Y. Nishiyama
High ︲ temperature oxidation behavior of Fe ︲ Ni ︲ Cr alloys with different Ni contents in air and steam at 700 ℃ was investigated. Oxidation mass gain in steam was higher than that in air. In both atmospheres oxidation mass gain tended to decrease with increas ing Ni content. However, the Ni concentration dependence of oxidation mass gain in air was complex, i.e., oxidation mass gain increased with increase in Ni content up to 35 ％ then decreased with higher Ni content. But oxidation mass gain of binary Ni ︲ 20Cr significantly increased. Such a complex oxidation behavior was not observed when alloys were oxidized in steam. The internal oxidation zone was locally formed in air, and a Cr 2 O 3 scale was found to develop on the areas without internal oxidation. The size of area, where an internal oxidation zone was developed, changed depending on Ni content. In steam, most of the surface area of alloys was covered by an internal oxidation zone. Cr content, 20 ％ , was considered to be insufficient but close to the critical Cr content for exclusive Cr 2 O 3 scale formation in air. The critical Cr content for exclusive Cr 2 O 3 scale formation was found to depend on alloy Ni content due to lower oxygen permeability in alloys with higher Ni content and the cross ︲ term effect for Cr outward diffu -sion. ［ doi:10 . 2320 / jinstmet.JB201705 ］ ）
{"title":"Oxidation Behavior of Fe-Ni-Cr Alloys at 700°C in Air and Steam","authors":"S. Hayashi, D. Takashima, Norifumi Kochi, Y. Nishiyama","doi":"10.2320/jinstmet.jb201705","DOIUrl":"https://doi.org/10.2320/jinstmet.jb201705","url":null,"abstract":"High ︲ temperature oxidation behavior of Fe ︲ Ni ︲ Cr alloys with different Ni contents in air and steam at 700 ℃ was investigated. Oxidation mass gain in steam was higher than that in air. In both atmospheres oxidation mass gain tended to decrease with increas ing Ni content. However, the Ni concentration dependence of oxidation mass gain in air was complex, i.e., oxidation mass gain increased with increase in Ni content up to 35 ％ then decreased with higher Ni content. But oxidation mass gain of binary Ni ︲ 20Cr significantly increased. Such a complex oxidation behavior was not observed when alloys were oxidized in steam. The internal oxidation zone was locally formed in air, and a Cr 2 O 3 scale was found to develop on the areas without internal oxidation. The size of area, where an internal oxidation zone was developed, changed depending on Ni content. In steam, most of the surface area of alloys was covered by an internal oxidation zone. Cr content, 20 ％ , was considered to be insufficient but close to the critical Cr content for exclusive Cr 2 O 3 scale formation in air. The critical Cr content for exclusive Cr 2 O 3 scale formation was found to depend on alloy Ni content due to lower oxygen permeability in alloys with higher Ni content and the cross ︲ term effect for Cr outward diffu -sion. ［ doi:10 . 2320 / jinstmet.JB201705 ］ ）","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"140 1","pages":"417-426"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73281537","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 : 2017-01-01DOI: 10.2320/JINSTMET.J2017027
Ryosuke Ozasa, Aira Matsugaki, Y. Isobe, Taro Saku, T. Nakano
Bone tissue has a highly anisotropic microstructure composed of biological apatite （ BAp ） and collagen fibrils, which is closely related to bone mechanical function. The formation of anisotropic bone microstructure is governed by bone - forming osteoblasts; therefore, establishment of isolation method of osteoblasts and assessment of their arrangement for generating bone tissue with optimally oriented microstructure during bone reconstruction are important. In this study, we established the isolation and culture conditions of mature osteoblasts derived from juvenile mice （ 2 - week - old ） . Osteoblasts from juvenile mice expressed significantly higher level of osteoblastic markers （ alkaline phosphatase, osterix, and osteocalcin ） than osteoblasts from neonatal mice, indicating that juvenile osteoblasts are promising materials for bone tissue engineering. Moreover, the mature osteoblasts aligned along the collagen molecule direction of substrate. This is the report that shows preferential orientation of mature osteoblasts isolated from juvenile mice. ［ doi:10 . 2320 / jinstmet.J2017027 ］
{"title":"Preferential Arrangement of Mature Osteoblast from Juvenile Mouse Calvariae on the Oriented Collagen Substrate","authors":"Ryosuke Ozasa, Aira Matsugaki, Y. Isobe, Taro Saku, T. Nakano","doi":"10.2320/JINSTMET.J2017027","DOIUrl":"https://doi.org/10.2320/JINSTMET.J2017027","url":null,"abstract":"Bone tissue has a highly anisotropic microstructure composed of biological apatite （ BAp ） and collagen fibrils, which is closely related to bone mechanical function. The formation of anisotropic bone microstructure is governed by bone - forming osteoblasts; therefore, establishment of isolation method of osteoblasts and assessment of their arrangement for generating bone tissue with optimally oriented microstructure during bone reconstruction are important. In this study, we established the isolation and culture conditions of mature osteoblasts derived from juvenile mice （ 2 - week - old ） . Osteoblasts from juvenile mice expressed significantly higher level of osteoblastic markers （ alkaline phosphatase, osterix, and osteocalcin ） than osteoblasts from neonatal mice, indicating that juvenile osteoblasts are promising materials for bone tissue engineering. Moreover, the mature osteoblasts aligned along the collagen molecule direction of substrate. This is the report that shows preferential orientation of mature osteoblasts isolated from juvenile mice. ［ doi:10 . 2320 / jinstmet.J2017027 ］","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"75 1","pages":"480-484"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81156501","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 : 2017-01-01DOI: 10.2320/JINSTMET.JE201603
Y. Kayanuma, Shoei Mizuhashi, Y. Shindo
Recycling of precious metals from scraps generated from manufacturing process have been widely done. The recycling process calls for maintenance of confidentiality of the scrap, use of isolated lots for the recycling operation, high recovery rates, short operation time and low treatment costs. In recent years, the recycling process has been facing three additional problems. The first is the reduction in the precious metal content in the scraps because of their substitution by other non ︲ ferrous metals. The second is the contamination of metals that are never contained in natural ores. They have been used for upgrading the product perfor - mance, but those contaminations make it difficult to extract and purify precious metals. The third is the enforcement of stringent environmental regulations in Japan, which prohibits the continuous use of certain chemicals such as nitric acid. This paper describes the work carried out by a precious metals recycling company to solve the aforementioned problems.
{"title":"The Present State and Problems of Precious Metals Recycling","authors":"Y. Kayanuma, Shoei Mizuhashi, Y. Shindo","doi":"10.2320/JINSTMET.JE201603","DOIUrl":"https://doi.org/10.2320/JINSTMET.JE201603","url":null,"abstract":"Recycling of precious metals from scraps generated from manufacturing process have been widely done. The recycling process calls for maintenance of confidentiality of the scrap, use of isolated lots for the recycling operation, high recovery rates, short operation time and low treatment costs. In recent years, the recycling process has been facing three additional problems. The first is the reduction in the precious metal content in the scraps because of their substitution by other non ︲ ferrous metals. The second is the contamination of metals that are never contained in natural ores. They have been used for upgrading the product perfor - mance, but those contaminations make it difficult to extract and purify precious metals. The third is the enforcement of stringent environmental regulations in Japan, which prohibits the continuous use of certain chemicals such as nitric acid. This paper describes the work carried out by a precious metals recycling company to solve the aforementioned problems.","PeriodicalId":17337,"journal":{"name":"Journal of The Japan Institute of Metals","volume":"12 1","pages":"152-156"},"PeriodicalIF":0.0,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74762354","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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