The microstructural evolution and wear properties of Ni60/high-aluminum bronze composite coatings with directional structure

Xiao-Tian Yang^1,2，Xiu-Qian Li¹，Qiang-Bin Yang³，Jun-Ling Duan¹，Xiao-Yue Fu^1,4，Heng-Li Wei¹，Wen-Sheng Li¹

1. College of Materials Science and Engineering,State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology2. Wenzhou Engineering Institute of Pump & Valve,Lanzhou University of Technology3. Chongqing Key Laboratory of Environmental Materials & Remediation Technologies,College of Chemistry & Environmental Engineering,Chongqing University of Arts and Sciences4. Department of Material and Chemical Engineering,College of Technology and Engineering,Lanzhou University of Technology

摘 要：The directional structure of Ni60/high-aluminum bronze composite coating was formed using induction remelting and forced cooling.The microstructural evolution and the characteristics of interface growth were studied.The results showed that the remelted coating formed metallurgical bonding with the substrate.The micros tructures changed from plane crystal to dendrite,cellular dendrite,fine cellular dendrite,and then to dendrite again with the increase in the cooling rate.The crystal grew along the heat flow direction and had（111） and（200）preferred orientations when the cooling rate was 1.886 ml-min^-1.mm^-2.The plane crystal,dendrite and cellular dendrite were mainly composed of compounds and solid solutions with Ni,Fe and Cu,and they were surrounded by strengthening phases composed of Cr,C and B.The grain boundary of directional structure coatings showed the characteristic of regular eutectic growth,but grain boundary of remelted coating presented characteristic of divorced eutectic growth.The wear resistance of directional structure coatings is better than that of remelted coating.

关键词：