摘要
采用输出波长为1064 nm、脉冲宽度为20 ns的调Q钕玻璃激光,对2A02航空铝合金板表层进行了激光冲击,用透射电镜及其高分辨像的傅里叶过滤像分析了激光冲击后样品表面的微结构演变,研究了激光冲击诱导的纳晶化行为与形成机理及其对表面性能的影响。结果表明,激光冲击能在2A02航空铝合金板表面形成直径为～100 nm的纳米晶;表面纳晶层的硬度比基体提高54.5%。分析认为2A02铝合金表面纳晶化过程是激光冲击超高应变率和超高能量共同作用下由位错和空位等非平衡缺陷诱导的晶粒分化过程。
The aero-aluminum alloy 2A02 was laser shocked by means of Q-switched Nd： glass laser setup with the 1064 nm output wave length and 20 ns short pulse.The microstructure evolution of the shocked layer was analyzed by using the transmission electron microscope（TEM） and the image of Fourier filtration（IFFT） images of high resolution electron microscopy（HREM）.The laser shock induced nano-crystallization behavior and its mechanism were analyzed,as well as its effect on surface hardness.The experimental results show that the nano-crystalline grains with about～100 nm in diameter are obtained on the surface layer of the laser shocked 2A02 aluminum alloy sheet.The hardness of the nano-crystallized surface is increased by 54.5% in comparison with that of the matrix.It is demonstrated that the nano-crystallization is the grain＇s smashing-up process induced by the non-equivalent defects such as dislocations and vacancies,due to the combination effect of the super strain rate and super-high power of laser shocking.
出处
《金属热处理》
CAS
CSCD
北大核心
2011年第9期22-26,共5页
Heat Treatment of Metals
基金
国家自然科学重点基金项目(50735001)
