纳米压/划痕表征激光渗氮层的弹塑性力学性能  

Elastic-plastic mechanical properties of laser nitriding layer on Ti6Al4V alloy characterized by nanoindentation and nanoscratch

作　　者：曹丽琴[1,2] 轩福贞[1] 王正东[1] 涂善东[1] 

机构地区：[1]燕山大学环境与化学工程学院,河北秦皇岛066004 [2]华东理工大学机械与动力工程学院,上海200237

出　　处：《材料热处理学报》2011年第11期157-160,共4页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金项目(507350001);河北省高等学校自然科学研究指导项目(Z2011120);上海市重点学科建设项目(B503)

摘　　要：利用脉冲式Nd:YAG激光在Ti6Al4V合金表面进行激光渗氮处理,借助纳米压痕和划痕试验表征渗氮层的弹塑性力学性能。结果表明,在钛合金表面成功制备了高硬度、高强度、枝晶状分布的渗氮层。同时,渗氮层内硬度、模量、强度以及应力-应变关系、摩擦系数等力学性能呈现出类似于激光渗氮层内氮元素扩散曲线的非均匀性空间分布规律。硬度和弹性模量之比以及纳米划痕试验结果表明,激光渗氮层的抗磨损性能随深度的增加逐渐降低,摩擦系数随着划入深度的增加,从0.2增加到0.4。Laser gas nitriding of Ti6Al4V was performed by pulsed Nd：YAG laser.Nanoindentation and nanoscratch instruments were used to quantitatively evaluate the elastic-plastic properties.Results indicate that dendrite structure in the nitriding layer is formed with high hardness,high strength and metallurgical bonding to the titanium alloy substrate.It is found that the hardness,elastic modulus,yield stress and stress-strain responseof the nitriding layer decrease gradually with depth.It is ascribed to the gradient diffusion of nitrogen along depth in the nitriding layer.Meanwhile,the ratios of hardness and elastic modulus by nanaoindentation and the nanoscratch experimentss show that the wear resistance of the nitriding layer deereases along its depth.The friction coefficients increase from 0.2 to 0.4 along depth.

关 键 词：激光渗氮 纳米压痕 纳米划痕 力学性能 

分 类 号：TG113.25[金属学及工艺—物理冶金]