(1. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001；
2. 哈爾濱工業(yè)大學(xué) 金屬精密熱加工國(guó)家級(jí)重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001)
摘 要: 采用水冷銅坩堝真空感應(yīng)熔煉(ISM)技術(shù)制備β型TiAl合金Ti-45Al-2Nb-1.5V-1Mo-0.3Y(摩爾分?jǐn)?shù)，%)及其復(fù)合材料Ti-45Al-2Nb-1.5V-1Mo-0.3Y(摩爾分?jǐn)?shù)，%)＋3%TiB2(體積分?jǐn)?shù))兩種材料，并對(duì)TiAl合金及其復(fù)合材料的顯微組織、力學(xué)性能和抗氧化性能進(jìn)行研究。結(jié)果表明：加入TiB2后，TiAl合金中的晶粒尺寸和層片間距都得到細(xì)化，顯微硬度、室溫和高溫抗拉強(qiáng)度提高，但室溫伸長(zhǎng)率略有下降，高溫時(shí)復(fù)合材料表現(xiàn)出良好的塑性；800 ℃循環(huán)氧化100 h后，TiAl合金和復(fù)合材料氧化表面均保持完整，未產(chǎn)生剝落；加入TiB2后，導(dǎo)致兩種材料表面氧化物的生長(zhǎng)形態(tài)發(fā)生變化，但兩種材料的氧化增量和氧化層厚度相近，因此，TiB2對(duì)氧化物的生長(zhǎng)形態(tài)有影響，但對(duì)抗氧化性能影響不大。
關(guān)鍵字: TiAl合金；顯微組織；力學(xué)性能；抗氧化性；TiB2
（1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China）
Abstract:TiAl-based alloy Ti-45Al-2Nb-1.5V-1Mo-0.3Y (mole fraction, %) and composites Ti-45Al-2Nb-1.5V-1Mo-0.3Y (mole fraction, %)＋3%TiB2 (volume fraction) were prepared by induction skull melting (ISM). The microstructure, mechanical properties and oxidation resistance were studied. The results show that the composites exhibit much finer lamellar colony size and lamellar spacing compared with matrix. The micro-hardness and tensile fracture strength are improved at room temperature and 800 ℃, while the tensile elongation decreases at room temperature. The composites show good plastics at 800 ℃. After oxidation in air at 800 ℃ for 100 h, the oxidation surfaces of matrix and composites show good quality with no micro-cracks observed. The growth morphologies of matrix oxidation surface change compared with those of composites. But the mass gain and thickness of oxide scale of composites are almost the same as those of matrix. So, TiB2 has some influence on the growth morphologies of oxide scale, but nearly has no influence on the oxidation resistance.
Key words: TiAl-based alloy; microstructure; mechanical property; oxidation resistance; TiB2
