激光增材制造单晶高温合金研究进展

镍基单晶高温合金具有良好的高温强度、抗氧化和抗腐蚀性能、抗蠕变性能和组织稳定性,被广泛应用于制造航空发动机和燃气轮机叶片。由于其工作条件复杂恶劣,采用有效手段修复单晶叶片可以大大提高其使用寿命。综述了激光增材制造技术制备单晶高温合金的研究现状,介绍了激光增材制造技术制备单晶合金的理论基础,以及控制其单晶凝固组织的困难和不足,着重综述了激光增材制造技术控制单晶高温合金凝固制造的方法,主要包括通过激光参数调控温度梯度及凝固速率,以及通过基体晶体取向控制晶粒外延生长。最后,展望了该领域未来的主要研究方向和发展前景。

Research Progress in Laser Additive Manufacturing Technology of Single Crystal Superalloy

It is well-known that nickel-based single crystal superalloys have excellent properties, including high temperature strength, oxidation and corrosion resistance, creep resistance, and structural stability. Therefore, they are widely used in blades of aircraft engines and gas turbines. Due to complicated and harsh working conditions, the service life of single crystal blades can be prolonged by efficient repair technology. In this paper, the status of research on laser additive manufacturing technology for single crystal superalloys was reviewed. The theoretical basis of the additive manufacturing for single crystal superalloy and the difficulties and shortages of controlling single crystal solidification structures were introduced. The methods of controlling solidification and manufacturing of single crystal superalloys by laser additive manufacturing technology were reviewed, mainly including controlling temperature gradient and solidification rate by laser parameters and controlling epitaxial growth of crystal grains by controlling the crystal orientation of substrates. Finally, the main research directions and development prospect of this field were prospected.