腐蚀介质条件下NiCrBSi/WC喷熔层的摩擦学性能研究

采用氧-乙炔火焰喷熔工艺,制备了碳化钨颗粒增强镍基合金喷熔层(NiCrBSi/WC),研究了它在腐蚀介质条件下的摩擦磨损行为与机理,并考察了载荷、滑动速度对其摩擦磨损性能的影响规律。研究结果表明:NiCrBSi/WC具有良好的耐腐蚀磨损性能,且当WC含量为20%时,腐蚀磨损率最低;WC含量超过20%后,由于喷熔层存在“腐蚀原电池”效应,其腐蚀磨损率增大。NiCrBSi/WC的腐蚀磨损率随载荷增加而变大,随速度增大而减小。载荷的增加使喷熔层的犁削磨损加剧,导致摩擦系数和磨损率增大;速度的增大造成摩擦界面温度上升,可生成摩擦转移膜,从而降低了喷熔层的磨损率。

Tribological Properties of NiCrBSi/WC Spray-welding Coatings in Corrosive Mediums

Tungsten carbide particles reinforced nickel-base alloys(NiCrBSi/WC) were prepared by oxygen-acetylene flame spray-welding technology.The friction and wear properties of NiCrBSi/WC coatings in corrosive mediums were studied and the effects of load and sliding speed on tribological properties were also researched.The research results show that NiCrBSi/WC composites have excellent anti-corrosive wear properties,and the wear rate is minimum when WC percent is 20%, but it increases as WC content is higher than 20% because of the effect of corrosive-galvanic battery in the composite coatings.The wear rates of the coatings increase with loads and decrease with sliding speeds.The ploughing wear becomes intense with the increase of load,which leads to the high friction coefficient and wear rate.The wear rate decreases when sliding speed increases because the increase of sliding speed may result in the increase of temperature and the formation of friction film on the worn surface,which protects the matrix from further wear,then the wear rate decreases.