(北京航空航天大學(xué) 材料科學(xué)與工程系，北京 100083)
摘 要: 較系統(tǒng)地研究了TiAl基合金激光快速熔凝組織細(xì)化特征及該類組織的超塑連接規(guī)律。結(jié)果表明，激光處理后試樣表面熔凝區(qū)的組織主要為胞狀枝晶組織，經(jīng)后續(xù)熱處理可轉(zhuǎn)變?yōu)榧?xì)小的等軸晶粒組織，并形成了良好的超塑連接條件。利用該表面組織對試樣進(jìn)行超塑擴散連接，探討了連接溫度、壓力和時間對連接效果的影響。表面細(xì)化組織試樣與整體細(xì)化組織試樣的超塑連接具有基本相同的連接規(guī)律。在連接溫度900 ℃，連接壓力60 MPa，連接時間1*!h條件下，可以實現(xiàn)試樣的超塑擴散連接。
關(guān)鍵字: TiAl基合金； 顯微組織； 激光表面處理；連接
laser surface melted TiAl intermetallic alloy
（Department of Materials Science and Engineering,
Beijing University of Aeronautics and Astronautics, Beijing 100083, P.R.China）
Abstract:The character of fine-grained structure obtained by laser surface processing and its rule of superplastic forming and diffusion bonding of TiAl basedalloy were investigated systemically. The results show that, after laser surface processing, a melt layer with cellular-dendrite structure is formed,which could transform into very fine-grained structure during the annealing treatment. Superplastic forming and diffusion bonding between the surfaces with fine-grained structure was carried out, with which the bonding effects brought by temperature, stress and time were discussed respectively. Both the sample with surface fine-grained structure and that with integrate fine-grained structure have the same rule essentially. The results show that, at the condition of 900℃ and 60MPa, sound superplastic diffusion bonding could be obtained after kept 1h.
Key words: TiAl based alloy； microstructure； laser surface treatment； bonding
