为了减小热喷涂层残余应力对涂层质量的不利影响,采用喷丸(砂)微粒轰击与高速电弧喷涂相互循环交替的工艺制备了Fe基非晶涂层,使涂层残余拉应力变为残余压应力,喷丸(砂)强化涂层表面残余应力由未处理涂层表面残余拉应力277 MPa分别变为残余压应力-177 MPa(-91 MPa)。利用电子扫描显微镜、纳米压痕仪、摩擦磨损试验机等分别对涂层的微观形貌、力学性能和摩擦磨损性能进行了测试。结果表明:经过微粒轰击后的涂层表面致密平整,组织结构密实,喷丸(砂)强化涂层的孔隙率仅为1.0%(1.5%),结合强度可达44.6 MPa(56.4 MPa),经过微粒轰击后涂层硬度、弹性模量及摩擦磨损性能都有所提升。喷丸强化涂层局部过度的轰击会使涂层结合强度及摩擦磨损性能略有下降。
The Fe-based amorphous coatings were fabricated by cyclic alternating process of high velocity arc spraying and shot and grit bombarding to decrease the negative impact from the residual stress of the thermal sprayed coating. The residual stress of the coating surface was obviously reduced from the tensile stress of 277 MPa (untreated coating) to the pressure stress of-91 MPa (grit blasting (GB) coating) and -177 MPa (shot peening (SP) coating). The micro morphology, mechanical and residual stress were investigated by XAM-3D, SEM and nano-test apparatus, respectively. The results show that the coatings exhibit a dense structure and smooth surface after particle bombarding. The porosity is only 1.5% and 1.0%, and the bonding strength of the GB coating and SP coating is 56.4 MPa and 44.6 MPa, respectively. The properties of micro-hardness, elasticity modulus and friction wear of the shot and grit bombarding coatings are improved. However, the partial excessive bombardment of the shot peening coming makes the bond strength and friction and wear performance degrade.