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4852 |
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Wednesday, May 11, 2016, Room 3E 12:20 PM Cold Gas Spraying III |
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Influence of phosphorus and tin content on various characteristics of cold sprayed copper coatings
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Yuichiro Yamauchi* / NHK Spring Co.,Ltd., Japan Shinya Miyaji/ NHK Spring Co., Ltd., Japan Masaru Akabayashi/ NHK Spring Co., Ltd., Japan Satoshi Hirano/ NHK Spring Co., Ltd., Japan Naoya Aikawa/ NHK Spring Co., Ltd., Japan Ryo Tanaka/ NHK Spring Co., Ltd., Japan Toshihiko Hanamachi/ NHK Spring Co., Ltd., Japan |
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The cold spray is a new coating technology that is expected as a novel industrial process. Conventional copper coatings made by cold spray are known as a brittle material while having a high tensile strength. In addition, electrical conductivity of the cold sprayed copper coating is also inferior as compared with that of bulk material. These behaviors are due to high dislocation density and fine crystal grains of the cold sprayed coating. In order to solve these problems, conventionally, it has been attempted to recover the metallic structure by heat treatment. However, heat treatment causes an increase in product cost due to a necessity of some equipments and an addition to manufacture process. In previous study, phosphorus content in copper is generally known as an element which significantly reduced the conductivity. On the other hand, tin content in copper produces an effect of changing the recrystallization temperature. Focusing on phosphorus and tin that significantly affect copper property, we have aimed at improving various characteristics of cold sprayed copper coating without heat treatment by using the optimization of impurity content in the production process of water atomized copper powder. As a result, we have achieved a dense cold sprayed coating with a copper powder which is suitably adjusted the content of phosphorus and tin. It is confirmed that the coating has not only high ductibility but equal electrical conductivity to bulk material. We concluded that dynamic recrystallizaion during cold spray coating process enhances the characteristics of copper coating. |