摘要
目前,对低压冷喷涂Al-Al_(2)O_(3)复合涂层的研究主要集中在工艺和性能方面,对颗粒的沉积特性和机理的研究较少。为此,利用低压冷喷涂技术沉积Al-Al_(2)O_(3)复合涂层,研究了不同载气温度对复合涂层沉积特性的影响规律,采用扫描电镜(SEM)、三维轮廓仪对复合涂层的厚度、表面形貌、显微组织进行了分析。结果表明:不同载气温度(300,400,500,600℃)制备的Al-Al_(2)O_(3)复合涂层厚度依次为213.34,321.62,920.64,986.97μm,复合涂层厚度随载气温度升高而增加,尤其当冷喷涂载气温度由400℃变为500℃时,沉积层厚度增幅达186.25%;复合涂层表面最大高度差H_(max)和粗糙度R_(a)随载气温度升高呈增加趋势,载气温度为400℃时复合涂层表面质量最优,当载气温度由400℃变为500℃时H_(max)和R_(a)增幅最大,分别为72.68%和52.22%,随载气温度的升高复合涂层表面质量下降;复合涂层中形变Al颗粒的扁平率随载气温度升高呈下降趋势,复合涂层中Al颗粒由塑性变形量较大的扁平状(300℃)逐渐变为塑性变形量较小的椭球形(600℃),随载气温度升高Al-Al_(2)O_(3)涂层的沉积率突增和颗粒扁平率下降归因于Al颗粒的热软化效应。
At present,the research on low-pressure cold sprayed Al-Al_(2)O_(3) composite coating mainly focused on the process and properties,and there was less research on the deposition characteristics and mechanism of particles.For this,the Al-Al_(2)O_(3) composite coating was deposited by low pressure cold spraying technology(LPCS).The effects of different carrier gas temperatures on the deposition characteristics of the composite coating were studied.The thickness,surface morphology and microstructure of the composite coating were analyzed by scanning electron microscope(SEM)and three-dimensional profiler.Results showed that the thicknesses of Al-Al_(2)O_(3) composite coating prepared by LPCS at different carrier gas temperatures(300,400,500 and 600℃)were 213.34,321.62,920.64,986.97μm,respectively.The thickness of composite coating increased with the increase of carrier gas temperature.Especially when the carrier gas temperature of cold spraying increased from 400℃to 500℃,the thickness of deposited coating was increases by 186.25%.The maximum height difference H_(max) and roughness R_(a) of the composite coating surface increased with the increase of carrier gas temperature.When the carrier gas temperature was 400℃,the surface quality of the composite coating was the best.When the carrier gas temperature rose from 400℃to 500℃,the increased amplitudes of H_(max) and R_(a) were the largest,72.68%and 52.22%,respectively.The surface quality of the composite coating decreased with the increase of carrier gas temperature.The flattening rate of deformed Al particles in the composite coating decreased with the increase of carrier gas temperature.Al particles in the composite coating gradually changed from flat shape with large plastic deformation(300℃)to ellipsoid shape with small plastic deformation(600℃).The sudden increase of deposition rate of Al-Al_(2)O_(3) coating and the decrease of particle flattening rate with the increase of carrier gas temperature were attributed to thermal softening effect of Al pa
作者
杨理京
付树仁
王少鹏
王培
翁子清
YANG Li-jing;FU Shun-ren;WANG Shao-peng;WANG Pei;WENG Zi-qing(Northwest Institute for Non-Ferrous Metal Research,Xi’an 710016,China;Shaanxi Rare Metal Material Surface Engineering Technology Research Center,Xi’an 710016,China;Zhejiang Metallurgical Research Co.,Ltd.,Hangzhou 310005,China)
出处
《材料保护》
CAS
CSCD
2022年第1期71-77,127,共8页
Materials Protection
基金
国家自然科学基金(51701165)
陕西省博士后基金(2018BSHQYXMZZ36)资助。
