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本研究的目的是通过提高环境温度来显著降低激光熔覆涂层的开裂敏感性,并揭示激光熔覆涂层中不同深度区域的残余应力分布规律。在25、400、600和800°C环境温度下通过激光熔覆技术在Ti6Al4V基体上制备了TiB和TiC增强的TiNi/Ti_2Ni双相基复合涂层。通过纳米压痕法详细测量了涂层不同深度区域残余应力的变化情况。结果显示,在25°C环境温度下制备的涂层中平均残余拉应力最大,达到2.90 GPa。随着环境温度的升高,涂层中的平均残余应力逐渐下降到1.34 GPa(400°C)、0.70 GPa(600°C)和0 GPa(800°C)。对于所有涂层,残余拉应力随着离涂层表面距离的增大而增大。环境温度的提高能有效降低涂层的开裂敏感性。
The purpose of this study is to significantly reduce the cracking susceptibility of laser cladding coatings by increasing the ambient temperature and to reveal the residual stress distribution in laser cladding coatings at different depths. TiB and TiC reinforced TiNi / Ti_2Ni dual phase composite coatings were prepared on Ti6Al4V matrix by laser cladding at 25,400,600 and 800 ° C ambient temperature. The variation of residual stress in different depth regions of coating was measured in detail by nanoindentation method. The results show that the average residual tensile stress in the coatings prepared at 25 ° C ambient is the largest, reaching 2.90 GPa. As the ambient temperature increases, the average residual stress in the coating gradually decreases to 1.34 GPa (400 ° C), 0.70 GPa (600 ° C) and 0 GPa (800 ° C). For all coatings, the residual tensile stress increases with distance from the coating surface. Increased ambient temperature can effectively reduce the cracking sensitivity of the coating.