Temperature-copper content induced wear mechanism transition in Cu/Ni60A composites

Abstract

Coppery blast furnace tuyere is easily damaged in high temperature wear environment. Preparing a Ni60A coating by plasma cladding is an effective method to improve its wear resistance and service life. Controlling the appropriate dilution rate is the key to obtain high-quality coatings. The existing research has no clear conclusion on the range of dilution rate of coating for coppery tuyere. In this paper, a series of Cu/Ni60A composites with different copper content (10 wt%, 20 wt%, 40 wt% and 60 wt%) were prepared to mimic Ni60A coatings exhibiting distinct dilution rate. Under the coupling change of temperature and copper content, the wear mechanism of Cu/Ni60A composites showed a complex transition law. Copper content, surface oxide layer (NiO or CuO) and high-temperature softening temperature were the decisive factors of wear transition. The applicable temperatures of Cu/Ni60A composites with low copper content (10 %, 20 %), middle copper content (40 %) and high copper content (60 %) were about 600 °C, 400 °C and 300 °C, respectively. Combined with the heat transfer analysis results, the suitable dilution rates for the coating applied to the inner wall (＜10 %) and front end (10 %-20 %) of tuyere was revealed.