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1193 |
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Copper based composite coatings produced by cold spray deposition |
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Silvano Rech / Veneto Nanotech, Italy Simone Vezzù / civen, italy Vanya Stoyanova/ civen, italy |
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As well known copper is a good conductor of heat and electricity, therefore, it has been long used in electromagnetic parts and for production of wires. It is also used as a bacteriostatic component in biomedical applications and in the food industry, but the pure copper hasn?t good mechanical properties as some application may demand. To improve the mechanical behavior, usually, copper based alloys or copper based composite materials are used. The deposition of copper by cold spray has shown a good results, in terms of low porosity and low oxide content on coatings, the mechanical properties, anyway, are quite poor. Different ceramic/copper powders mixtures have been studied in order to improve the mechanical properties of the thick coatings, such as wear resistance and hardness. The size and the percentage of the ceramic particles were optimized, in order to obtain a good sprayability of the powder mix and good distribution of the ceramic phase in the final coating. The depositions were made by nitrogen cold spray system on aluminium substrates. Metallographic investigation, by LOM and SEM, were carried out to evaluate the homogenization, adhesion and the porosity of the composite coatings. Mechanical characterization such as apparent hardness and microhardness, as well as wear resistance were carried out. The electrical properties and the corrosion resistance of the coatings were studied, too. |