摘要
目的 提高TC4钛合金与TiN涂层的结合强度。方法 通过实验研究的方法探索激光冲击强化对TC4钛合金表面TiN涂层界面结合性能的影响。首先,采用不同激光冲击参数(光斑搭接率、功率密度)对其表面进行前处理。利用Wyko NT 1100型非接触式光学轮廓仪(NCOP)测量TC4钛合金试样的表面几何形貌和粗糙度。利用X350A型X射线残余应力测定仪测量TC4钛合金表面残余应力。利用HXD-1000TMSC/LCD型显微硬度计测量冲击表面的显微硬度。其次,采用离子镀膜技术在激光冲击区域制备TiN薄膜,并利用WS-2005型涂层附着力自动划痕仪测试TiN涂层与TC4钛合金的界面结合力,分析激光冲击前处理对TiN涂层界面结合性能的影响。最后,通过摩擦磨损试验验证激光冲击强化前处理改善涂层界面结合性能的有效性。结果 在动态加载载荷为50 N、加载速率为50 N/min、划痕长度为4 mm的测试条件下,未经激光冲击处理的TiN涂层与基体的结合力为28.9 N,经激光冲击前处理后A1—A5试样的结合力分别提升至32.3、33.2、34.9、36.8、39.6 N,前处理对界面结合力的提升幅度分别为11.76%、14.88%、20.76%、27.34%、37.02%。在试验负载为7.5 N、往复行程为5 mm、往复频率为2 Hz、测试时间为25 min的干摩擦条件下,A1—A5试样的磨损率分别降至3.79×10^(-5)、9.8×10^(-6)、8.82×10^(-6)、4.32×10^(-6)、1.24×10^(-6)mm^(3)/(N·m)。结论 激光冲击强化前处理可以有效提高TiN涂层的界面结合力,提高涂层的耐磨损性能。激光参数中光斑搭接率对涂层界面性能的影响最显著,50%的搭接率可使激光强化效果均匀,在50%搭接率、6.43 GW/cm^(2)功率密度的激光参数作用下可以获得最优的界面结合性能和耐磨效果。
This paper aims to improve the bonding strength of TC4 titanium alloy and TiN coatings, the effect of laser shock peening on the interfacial bonding properties of TiN coatings on the surface of TC4 titanium alloy is explored through experimental research. Firstly, the surface was treated with different laser parameters(spot overlap ratio and power density), and the surface geometry and roughness of TC4 titanium alloy samples were measured by Wyko NT 1100 non-contact optical profilometer(NCOP), the surface residual stress of TC4 titanium alloy was measured by X350A X-ray residual stress tester, and the microhardness of impact surface was measured by HXD-1000TMSC/LCD microhardness tester;Secondly, the ion plating technology was used to prepare TiN coatings in the laser shock region, and the interfacial adhesion between the TiN coating and TC4 titanium alloy was measured by WS-2005 film adhesion automatic scratch instrument to analyze the effect of laser shock pre-treatment on the interfacial adhesion of tin coatings;Finally, the friction and wear test was used to verify the effectiveness of the laser shock strengthening pre-treatment to improve the bonding performance of the coating interface. The following experimental data were obtained: Under the test conditions of a dynamic load of 50 N, a rate of 50 N/min, and a scratch length of 4 mm, bonding force of TiN coating and substrate of the sample without laser shock treatment was 28.9 N, but after pre-treatment of laser shock peening, the adhesion was increased to 32.3 N, 33.2 N, 34.9 N, 36.8 N and 39.6 N, and the increase of interfacial adhesion by pretreatment was 11.76%, 14.88%, 20.76%, 27.34% and 37.02% respectively;Under dry friction conditions with a load of 7.5 N, a reciprocating stroke of 5 mm, a reciprocating frequency of 2 Hz, and a test time of 25 min, the wear rate of each sample was reduced to 3.79×10^(-5)mm^(3)/(N·m), 9.8×10^(-6)mm^(3)/(N·m), 8.82×10^(-6)mm^(3)/(N·m), 4.32×10^(-6)mm^(3)/(N·m)and 1.24×10^(-6)mm^(3)/(N·m) respectively. The experimental results show that the pre-treatment of laser shock peening has an effective function of improving the interfacial bonding performance of TiN coatings on the surface of TC4 titanium alloy. The results of the friction and wear test indicate that the synergistic effect of laser shock and TiN coating significantly reduces the friction coefficient and wear rate of the TC4 titanium alloy, and improves the wear resistance of the coating. Among the laser parameters, the spot overlapping rate has the most significant effect on the interface performance of the coating. When the overlap rate is 50%, the surface treatment effect of the material has good uniformity, and the best interface bonding performance and wear resistance effect can be obtained under the action of the laser parameters of 50% overlapping rate and 6.43 GW/cm^(2) power density.
作者
徐硕
苏波泳
花国然
王恒
曹宇鹏
XU Shuo;SU Bo-yong;HUA Guo-ran;WANG Heng;CAO Yu-peng(School of Mechanical Engineering,Nantong University,Nantong 226019,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2022年第3期315-325,共11页
Surface Technology
基金
国家重点研发计划项目(2019YFB2005300,2019YFB2005305)
江苏省高校自然科学研究项目(20KJB460010)
江苏省研究生科研创新计划项目(KYCX21_3081)。
