新型损伤容限型钛合金TC21稀土催化固体渗硼

Characteristics of RE-B Surface Diffusion Process on the New Damage Tolerance

摘要:

采用固体粉末渗硼法对新型损伤容限型钛合金TC21表面进行稀土催化化学热处理，通过扫描电镜（SEM）、X射线衍射（XRD）、能谱（EDS）与金相显微镜（OM）研究了渗层组织形貌和物相组成。结果表明：钛基表面渗硼层包括以整体薄壁状在基体外层分布的TiB2和以须状晶形式在次表层分布的TiB双强化渗层，渗层与基体结合紧密；渗剂中稀土含量对渗层性能的影响存在有最佳值；且发现此方法实现了钛合金TC21表面B、C共渗

Abstract:

The solid-state boriding of new damage tolerance TC21 titanium alloy was carried out to harden surface layers through rare earth (RE) B diffusion process. By means of SEM, XRD, OM and EDS, the microstructure and morphology of boride coatings were investigated. The results indicate that boride layers include a monolithic titanium diboride (TiB2) at the top and a titanium boride (TiB) sub-layer that mostly consisted of TiB whiskers combining with titanium matrix closely. Meanwhile, the contents of RE in boriding medium possess a considerably optimal value. B and C surface co-diffusion with RE on TC21 alloy can be realized by this method