(1. 燕山大學(xué) 先進(jìn)鍛壓成形技術(shù)與科學(xué)教育部重點(diǎn)實(shí)驗(yàn)室，秦皇島 066004；
2. 燕山大學(xué) 國(guó)家冷軋板帶裝備及工藝工程技術(shù)研究中心，秦皇島 066004)
摘 要: 以Ti-22Al-25Nb(摩爾分?jǐn)?shù)，%)預(yù)合金粉末為實(shí)驗(yàn)初始原料，采用放電等離子燒結(jié)工藝(SPS)方法，在溫度為950~1200 ℃，保溫時(shí)間為10~20 min，壓力為35~80 MPa的條件下制備晶粒小、組織致密的粉末冶金Ti-22Al-25Nb合金。研究燒結(jié)溫度、燒結(jié)壓力和保溫時(shí)間對(duì)預(yù)合金粉末致密化過(guò)程的影響，分析粉末的燒結(jié)致密化機(jī)理，揭示燒結(jié)溫度、燒結(jié)壓力和保溫時(shí)間對(duì)Ti-22Al-25Nb燒結(jié)合金的相對(duì)密度、相組成、顯微組織以及力學(xué)性能的影響規(guī)律，明確燒結(jié)合金的室溫?cái)嗔褭C(jī)制。結(jié)果表明：經(jīng)950 ℃、80 MPa、10 min燒結(jié)的Ti-22Al-25Nb合金相對(duì)密度達(dá)到99.43%，具有更優(yōu)異的綜合力學(xué)性能，其室溫伸長(zhǎng)率、屈服強(qiáng)度和抗拉強(qiáng)度分別達(dá)到9.38%、933.57 MPa和990.01 MPa。
關(guān)鍵字: Ti-22Al-25Nb合金；放電等離子燒結(jié)；致密化；力學(xué)性能
（1. Education Ministry Key Laboratory of Advanced Forging and Stamping Technology and Science, Yanshan University, Qinhuangdao 066004;
2. National Engineering Research Center for Equipment and Technology of C.S.R, Yanshan University, Qinhuangdao 066004, China）
Abstract:Ti-22Al-25Nb (mole fraction, %) pre-alloyed powders were used as the experimental starting materials. A powdery metallurgy Ti-22Al-25Nb alloy with fine grain size and dense microstructure was prepared using the spark plasma sintering process (SPS) method at the temperature of 950-1200 ℃, holding time of 10-20 min and pressure of 35-80 MPa. The effects of sintering temperature, sintering pressure and holding time on the densification of pre-alloyed powders were studied. The sintering densification mechanism was analyzed. The influences of sintering temperature, sintering pressure and holding time on the relative density, phase composition, microstructure and mechanical properties of the sintered Ti-22Al-25Nb alloy were revealed. In addition, the room temperature fracture mechanism of the sintered alloy was clarified. The results show that the relative density of the Ti-22Al-25Nb sintered alloy at (950 ℃, 80 MPa, 10 min) reaches 99.43%, and it has better comprehensive mechanical properties. The room temperature elongation, yield strength and tensile strength reach 9.38%, 933.57 MPa and 990.01 MPa, respectively.
Key words: Ti-22Al-25Nb alloy; spark plasma sintering; densification; mechanical property
