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发展了一种新的强化方法基于激光冲击的纳米颗粒注入强化,即利用激光冲击产生的GPa量级压力将预置的纳米WC颗粒注入铝合金表面实现复合强化。激光冲击强化技术利用光致冲击波作用材料表面,引入残余应力,提高材料表面性能。作为一种冷加工手段,这种方法避免了铝合金常规热强化方法容易产生的低熔点元素烧损、气孔、裂纹等缺陷,也避免了常规添加纳米材料强化时纳米颗粒由于熔点较低所造成的熔化凝固而失去纳米特性的问题。研究了激光冲击纳米WC颗粒的工艺、参数影响,复合强化层的硬度、残余应力和摩擦学性能等。研究表明,激光冲击注入WC纳米颗粒增强复合涂层表面硬度相对初始状态提高了20%,表面残余应力状态由拉应力状态转变为压应力状态,其耐磨性是原始铝合金的5倍,是单纯激光冲击的1.5倍。
A new enhancement method based on laser shock nanoparticle implantation has been developed, which utilizes the GPa pressure generated by laser shock to inject the prefabricated nano-WC particles into the surface of the aluminum alloy for composite strengthening. Laser shock enhancement technology uses photo shock waves to act on the surface of the material, introducing residual stresses and improving the surface properties of the material. As a cold processing method, this method avoids defects such as low melting point elements, pores, cracks and the like easily generated by the conventional heat-strengthening method of the aluminum alloy and avoids the defects that the nanoparticles have lower melting point when the conventional nano-material is added Melting solidification loss of nano-characteristics of the problem. The effects of laser impact on nano-WC particles, parameters, hardness, residual stress and tribological properties of the nanocomposites were studied. The results show that the surface hardness of the WC nano-particle reinforced composite coating increases by 20% compared with the initial state, and the surface residual stress state changes from tensile stress to compressive stress state. The wear resistance is five times that of the original aluminum alloy and is 1.5 times the impact of pure laser.