(华中科技大学 材料成形与模具技术国家重点实验室，武汉 430074)
摘 要: 采用激光喷丸强化技术在镍铝青铜合金(NAB)表面形成细晶层，采用 XRD、SEM、EBSD、TEM 等方法对其组织结构进行表征，并通过浸泡腐蚀试验研究激光喷丸处理对于NAB合金耐腐蚀性能的影响。结果表明：激光喷丸处理能够使得合金表层晶粒细化、小角度晶界比例增多以及位错增值。当激光光斑能量分别为3 J和6 J时，试样表面硬度相对于基体硬度分别提升31.5%和41.8%，合金表层硬度提升是由于晶粒细化、位错增值和残余压应力场的共同作用。除此之外，浸泡腐蚀结果表明激光喷丸处理能够改善合金的耐腐蚀性能，这是由晶粒细化导致的。
关键字: 镍铝青铜；激光喷丸；组织；硬度；耐腐蚀性能
（State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:A fine grained layer formed on the surface of nickel-aluminum-bronze alloy (NAB) by laser peening. The microstructure was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM). The effect of laser shot peening on the corrosion resistance of NAB alloy was studied by immersion corrosion test. The results show that the laser peening results in the formation of equiaxed fine grains, and increases the low-angle boundaries and dislocation densities in the surface layer. When the laser spot energy is 3 J or 6 J, the surface hardness of the sample is 31.5% or 41.8% higher than that of the substrate, respectively. The increase in the hardness of the alloy surface is due to the combined effect of grain refinement, dislocation increment and residual compressive stress. Besides, the static immersion corrosion test indicates that laser shot peening can improve the corrosion resistance of NAB alloy, which may attributed to the grain refinement.
Key words: nickel aluminum bronze; laser peening; microstructure; hardness; corrosion resistance
