HARDNESS AND MODULUS OF ELASTICITY OF BRUSH PLATED NICKLE COATING BY NANOINDENTATION TESTING

Wang Hongmei  Xu Binshi  Ma Shining  Dong Shiyun

(National Key Laboratory for Remanufacturing, Armored Force Engineering Institute, Beijing 100072)

Li Xiaoying

(School of Metallurgy and Materials, University of  Birmingham, Birmingham B152TT)

Abstract: A new type nano test system is introduced, the test principle and the indentation data analysis method are described. It is used to test the micro mechanical properties of brush plated Ni coating on steel, such as hardness, modulus of elasticity and anti-indentation creep property, and the regularities of mechanical properties distribution with coating thickness are researched. The results show that the coating exhibits uniform mechanical properties throughout its thickness, with the exception of a few regions with low hardness and modulus due to some flaws and a few regions with high hardness and modulus on the surface and subsurface. The average hardness and modulus of elasticity of Ni coating are 7.02 GPa and 183GPa respectively, thereinto the hardness is 2.9 times of steel. The Ni coating has greater resistance to indentation creep than steel under the test condition. These results supply useful data for process improvement, new type material development and application expansion.

Key words: Nanoindentation  Hardness  Modulus of elasticity  Brush plated coating

CLC No: TH117  TG174.4

国家自然科学基金(50235030)和中英科技合作基金(2002M3)资助项目. Received 20040511, received in revised form 20041115