HVOF喷涂工艺参数对WC-10%Co4%Cr涂层孔隙率的影响  

Research on Influence of HVOF Spraying Process Parameters on Porosity of WC-10%Co4%Cr Coating

作　　者：宋灿 丁婕 雷勇 余伟 韩萌 Song Can;Ding Jie;Lei Yong;Yu Wei;Han Meng(Zigong Tungsten Carbide Co.,Ltd.,Zigong Sichuan 643000,China;Zigong Cemented Carbide Co.,Ltd.,Zigong Sichuan 643000,China)

机构地区：[1]自贡长城表面工程技术有限责任公司,四川自贡643000 [2]自贡硬质合金有限责任公司,四川自贡643000

出　　处：《硬质合金》2022年第3期189-194,共6页Cemented Carbides

基　　金：四川省科技计划资助项目《含钒钛激光熔覆粉体材料制备关键技术研究及示范应用》(2022YFG0101)。

摘　　要：本文在常规WC-10%Co4%Cr(质量分数)粉末喷涂工艺基础上,通过改变煤油流量、氧气流量、喷涂距离三个主要工艺参数,采用JP5000超音速火焰喷涂系统进行了一组三因素三水平的正交实验。对涂层孔隙率进行正交分析,确定了喷涂距离是影响涂层孔隙的主要因素。结果表明,在常用的喷涂距离300~360 mm中,300 mm喷涂距离的涂层孔隙率可达到1%以下。在喷涂距离300 mm、煤油流量26 L/h、氧气流量945 L/min的最优参数下,涂层孔隙率为0.76%。结合金相厚度以及显微维氏硬度分析机理,得出喷涂距离300 mm的粒子具有更高的动能,以及更明显的粒子筛选效应,使得缺陷粒子不易沉积在基体表面,获得的涂层具有更低的孔隙率,涂层的硬度均匀性更好。在相同的喷涂距离下,通过提高煤油和氧气流量可以获得较高粒子动能和筛选效应。On the basis of the conventional WC-10%Co4%Cr(mass fration)powder spraying process,this study adopted the JP5000 high velocity oxygen fuel(HVOF)spraying system to conduct a set of three-factor and three-level orthogonal experiments by changing the three main spraying process parameters of kerosene flow,oxygen flow,and spraying distance.The orthogonal analysis of the coating porosity determined that the spraying distance was the main influencing factor affecting the pores of the coating.The results reveal that in the common spraying distance range of 300-360 mm,the coating porosity at a spraying distance of 300 mm can be less than 1%.Under a spraying distance of 300 mm,kerosene flow of 26 L/h,and oxygen flow of 945 L/min,the coating porosity of 0.76%can be achieved.In light of the metallographic thickness and Vickers hardness(HV),the mechanism was analyzed.It is concluded that the particles at a spraying distance of 300 mm have higher kinetic energy as well as a more significant particle screening effect,and thus the defective particles are not prone to deposit on the surface of the substrate,which means the obtained coating has a lower porosity,and the hardness uniformity of the coating is better.At the same spraying distance,a higher flow of kerosene and oxygen can lead to higher particle kinetic energy and better screening effects.

关 键 词：超音速火焰喷涂 热喷涂工艺参数 涂层孔隙率 粒子速度 

分 类 号：TG174.4[金属学及工艺—金属表面处理]