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采用电弧离子镀(AIP)技术在K417G合金表面制备了NiCrAlYSi涂层,利用HRS-2M型往复磨损试验机测试了K417G合金及NiCrAlYSi涂层室温至400℃以下的摩擦磨损特性,利用扫描电镜(SEM),能谱分析(EDS)和X射线衍射(XRD)等手段对合金和涂层的磨损表面形貌和横截面形貌进行观察和分析。结果表明:K417G合金的磨损率低于NiCrAlYSi涂层,300℃以下,合金摩擦系数高于涂层。室温下,合金和涂层磨损机制是疲劳脱层和环境致脆,环境致脆磨损机制源于室温空气中Ni_3Al相的环境脆性;磨损过程中,磨损表面形成的新鲜表面中的Ni_3Al相中的Al~+与水汽反应生成原子态H且逐渐聚集,导致氢致环境脆性,并逐渐作用于磨损表面;磨损表面的裂纹源在γ/γ’界面处形核,裂纹既沿着γ/γ’界面扩展,又进入γ’晶粒,呈现沿晶和穿晶混合状。随磨损温度升高,Ni_3Al相的环境脆性消失,合金和涂层磨损表面的环境致脆特征消失,磨损机制转变为黏着、犁沟、块状剥落和氧化磨损机制。
The NiCrAlYSi coating was prepared on the surface of K417G alloy by arc ion plating (AIP). The tribological properties of the coating were tested by HRS-2M reciprocating wear tester at room temperature up to 400 ℃. The scanning electron microscopy ), Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to observe and analyze the wear surface morphology and cross-sectional morphology of the alloy and coating. The results show that the wear rate of K417G alloy is lower than that of NiCrAlYSi coating and below 300 ℃, the friction coefficient of alloy is higher than that of coating. At room temperature, the wear mechanism of alloy and coating is fatigue delamination and environment brittleness, and the mechanism of environment brittle wear originates from the environment brittleness of Ni_3Al phase in air at room temperature. In the wear process, the Ni_3Al phase in the fresh surface formed by wear surface Al ~ + reacts with water vapor to generate atomic H and gradually accumulates, resulting in hydrogen-induced brittleness and gradually acting on the wear surface. Cracks at the worn surface nucleate at the γ / γ ’interface, Interface expansion, and into the γ ’grain, showing intergranular and transcrystalline mixed shape. With the increase of the wear temperature, the environment brittleness of Ni 3 Al phase disappeared, the brittleness of the environment on alloy and coating wear surface disappeared, and the wear mechanism was changed to sticking, furrowing, massive exfoliation and oxidation wear mechanism.