钛合金表面镍包石墨喷涂层的耐磨性能

Wear Resistance of Thermal Spraying Nickel-Coated Graphite Layer on Titanium Alloy

为了提高钛合金的表面耐磨性,利用氧乙炔热喷涂枪,在TC4合金表面上制备出镍包石墨涂层。采用MXP-2000型销盘式摩擦磨损实验机,进行钛合金及其镍包石墨涂层的干摩擦磨损实验,并利用扫描电镜对磨损表面进行观察和分析。实验结果发现,镍包石墨涂层的摩擦系数只有钛合金的一半左右,前者磨损量为后者的1/6,说明镍包石墨涂层可以大大提高钛合金的表面耐磨性能。TC4合金的磨损机制以黏着磨损为主,喷涂层的磨损机制以磨粒磨损为主,喷涂层中的石墨润滑相是其耐磨性高的主要原因。

In order to improve wear resistance of titanium alloy, by using an acetylene blowtorch of thermal spray apparatus, a process of thermal spraying nickel-coated graphite layer on TC4 alloy substrate is carried out. An MXP - 2000 type pin-on-disc wear tester is used to test the dry sliding friction behavior of TC4 alloy and nickel-coated graphite layer. The morphology of worn surface is examined by using a scanning electron microscope. The results of experiments indicate that the friction coefficient of nickel-coated graphite layer is a half of that of titanium alloy and worn loss of nickel-coated graphite layer is one sixth of that of titanium alloy. It means that nickel-coated graphite layer can greatly improve wear resistance of titanium alloy. The wear mechanism of titanium alloy is adherence wear and the wear mechanism of nickel-coated graphite layer is particle wear. The lubricant graphite in thermal spraying layer plays an important role for wear resistance improvement.