【摘要】 采用电火花表面沉积技术,在CrNi3MoVA钢表面沉积NiCrAlY涂层。利用纳米压痕仪和摩擦磨损试验机分别测试了CrNi3MoVA钢和NiCrAlY涂层的硬度、弹性模量和摩擦系数,并用SEM和EDS研究了磨损前后的形貌和成分。结果表明电火花沉积NiCrAlY涂层包含β-NiAl和γ-Ni两相,涂层是由柱状晶组成的微晶涂层;NiCrAlY涂层的硬度较CrNi3MoVA钢提高了22%,而弹性模量较CrNi3MoVA钢降低了21%;当摩擦副为淬火G15钢球,加载量为10N,往复行程为10mm,往复速率为600r/min时,CrNi3MoVA钢平稳摩擦系数为0.65~0.75,而NiCrAlY涂层平稳摩擦系数为0.45~0.55,CrNi3MoVA钢表面沉积NiCrAlY涂层对其具有明显的减摩耐磨作用,涂层表面较高的硬度和高速摩擦中形成的粘附力强的薄氧化物层是其耐磨的主要原因;CrNi3MoVA钢的磨损机制主要为粘着磨损,而NiCrAlY涂层为微切削磨料磨损。更多还原

【Abstract】 A NiCrAlY coating was electrospark deposited on surface of a CrNi3 MoVA steel.The hardness,elasticity modulus and friction coefficient of the CrNi3 MoVA steel and NiCrAlY coating were tested by employing the nanoindentor and the friction and wear testing machine,respectively,and then morphologies and composition were investigated before and after wearing by utilizing scanning electron microscopy(SEM)equipped with energy dispersive X-ray spectrum(EDS).The results indicated that the NiCrAlY coating with columnar structure,composed ofβ-NiAl andγ-Ni,belongs to microcrystal one.The hardness of the NiCrAlY coating increased by 22%than the CrNi3 MoVA steel whilst the elasticity modulus reduced by 21%;when the quenched G15 steel ball was used as the friction pair under the wear condition that the load was 10 N,the reciprocating travel was 10 millimeter and the velocity was 600 rounds per minute,the steady friction coefficient of the CrNi3 MoVA steel was 0.65-0.75 while that of the NiCrAlY coating was 0.45-0.55.Therefore the NiCrAlY coating electrospark deposited on the CrNi3 MoVA steel has the function of antifriction and wear resistance mainly due to its higher hardness and good adherent thin surface oxide layer formed during high-speed friction;the mechanism of the CrNi3 MoVA steel can be characterized as adhesive wear while that of the NiCrAlY coating is microcutting abrasive wear.更多还原