中国激光, 2019, 46 (8): 0802006, 网络出版: 2019-08-13
激光熔覆温度场和CeO2、TiO2对材料相变的影响 下载: 1024次
Effects of Temperature Field and CeO2/TiO2 on Material Phase Transition in Laser Cladding
激光技术 激光熔覆 数值模拟 Ni基合金 相变 显微组织 laser technique laser cladding numerical simulation Ni-based alloy phase transition microstructure
摘要
针对单道激光熔覆,利用数值模拟技术得到了激光熔覆过程的温度场;在Q235钢表面制备了Ni基激光熔覆层,基于材料相变理论分析了熔覆层不同深度位置微观组织的形成机理,并研究了添加CeO2、TiO2纳米颗粒对熔覆层组织的影响。结果表明:在激光熔覆过程中,在激光辐照和热传导的共同作用下,熔覆层和基体不同深度区域因温度变化的差异而发生不同类型的相变,从而得到不同的微观组织;在熔覆粉末中添加CeO2、TiO2纳米颗粒,可以通过影响材料的相变过程而改变熔覆层的化学组成和微观结构,提高形核率,得到组织均匀细小的熔覆层。
Abstract
For single laser cladding, the temperature field of the laser cladding was obtained by numerical simulation. Ni-based laser cladding layers were prepared on the surfaces of Q235 steel substrates by laser cladding experiments. Based on the theory of material phase transition, the formation mechanism of the microstructure at different depths of the cladding layer was analyzed, and the effect of adding CeO2 and TiO2 nanoparticles on the cladding structure was studied. The results show that in the process of laser cladding, under the combined actions of laser irradiation and heat conduction, the temperature variation characteristics of the cladding layer and matrix at different depths are different. This leads to different types of phase transitions, resulting in different microstructures. The addition of CeO2 and TiO2 nanoparticles to the cladding powder can change the chemical composition and microstructure of the cladding structure by influencing the phase transition process of the material,the nucleation rate is improved, and an uniform and fine cladding layer is obtained.
任仲贺, 武美萍, 崔宸, 夏思海. 激光熔覆温度场和CeO2、TiO2对材料相变的影响[J]. 中国激光, 2019, 46(8): 0802006. Zhonghe Ren, Meiping Wu, Chen Cui, Sihai Xia. Effects of Temperature Field and CeO2/TiO2 on Material Phase Transition in Laser Cladding[J]. Chinese Journal of Lasers, 2019, 46(8): 0802006.