摘要
激光功率是影响熔覆层质量的重要因素,为揭示激光功率对Ti6Al4V/NiCr-Cr_(3)C_(2)复合涂层成形质量、微观组织及耐磨性能等多方面的影响规律,采用同轴送粉、多道搭接激光熔覆技术在Ti6Al4V基材表面熔覆NiCr-Cr_(3)C_(2)粉末制备出碳化钛增强钛基复合涂层。通过渗透探伤、光学显微镜、X射线衍射仪、扫描电子显微镜及配套能谱仪等测试与表征方法分析熔覆层表面裂纹、截面形貌、孔隙率、稀释率、几何特征以及微观组织等。通过维氏显微硬度计和旋转式摩擦磨损试验机测试熔覆层显微硬度和耐磨性能,最后综合成形、组织与性能等方面的影响对熔覆层质量进行评价。结果表明,激光功率对熔覆层成形质量的影响显著。激光功率为1100 W和1300 W时熔覆层表面存在大量裂纹、气孔等缺陷。随着激光功率提高,熔覆层的熔高、熔宽、熔深及稀释率等均不断提高,裂纹率、孔隙率等持续降低。激光功率对涂层内物相种类的影响较小,主要物相为增强相TiC和基体相CrTi_(4)。激光功率为1500 W和1700 W时熔覆层的硬度相对较高,且磨损率较低。综合考虑激光功率对熔覆层的多方面影响,最后确定最优激光功率为1500 W,在此激光功率下制备出的熔覆层具有相对较好的成形质量和优异的耐磨性能。
Laser power is an important factor affecting the quality of the cladding coatings.In order to reveal the influence of laser power on the forming quality,microstructure,and wear resistance of Ti6Al4V/NiCr-Cr_(3)C_(2) composite coating,multi-track overlapping TiC reinforced composite coatings were prepared on the surface of Ti6Al4V substrate by laser cladding technology with coaxial powder feeding.The surface cracks,cross-section morphology,porosity,dilution rate,geometric characteristics,and microstructure of the cladding coatings were analyzed by penetration detection,optical microscopy,X-ray diffraction,and scanning electron microscopy(SEM)with energy dispersive spectrometer(EDS).Vickers microhardness tester and friction and wear tester were used to measure the microhardness and wear resistance of the cladding coatings.Finally,the quality of the cladding coatings was evaluated based on the influence of forming,microstructure and performance.The results showed that the laser power had a significant effect on the forming quality of the cladding coating.When the laser power was 1100 W and 1300 W,there were many defects such as cracks and pores on the surface of the cladding coating.With the increase of laser power,the melting height,melting width,melting depth,and dilution rate of the cladding coating were improved continuously.However,the crack rate and porosity continued to decrease.The laser power had little effect on the types of phases in the coatings,and the main phases were the reinforcement phase TiC and the matrix phase CrTi_(4).When the laser power was 1500 W and 1700 W,the hardness of the cladding coating was high,and the wear rate was low.Considering the influence of laser power on the cladding coatings in many aspects,the optimal laser power was finally determined as 1500 W.The cladding coating prepared under this laser power had good forming quality and excellent wear resistance.
作者
张志强
杨倩
于子鸣
张天刚
路学成
王浩
ZHANG Zhiqiang;YANG Qian;YU Ziming;ZHANG Tiangang;LU Xuecheng;WANG Hao(School of Aeronautical Engineering,University of Civil Aviation University of China,Tianjin 300300,China;School of Mechanical Engineering,Tianjin University of Technology and Education,Tianjin 300222,China)
出处
《材料导报》
EI
CSCD
北大核心
2024年第2期178-184,共7页
Materials Reports
基金
航空科学基金(2020Z049067002)
天津市教委科研计划项目(2020KJ020)
国家自然科学基金(51905536)
天津市科技计划项目(21YDTPJC00430)。
