祝寶軍1，秦明禮1，黃培云1
(1.中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083;
2.長(zhǎng)沙交通學(xué)院 汽車和機(jī)電工程系，長(zhǎng)沙 410076;
3.北京科技大學(xué) 材料科學(xué)與工程學(xué)院， 北京 100083)
摘 要: 通過(guò)非自耗磁控電弧爐熔鑄和700℃，20h高溫退火處理， 制備出了含鉻量為18%～30%(質(zhì)量分?jǐn)?shù))的含TiCr2 Laves相過(guò)共析鈦鉻合金，并研究了合金的組織變化規(guī)律。結(jié)果表明，穩(wěn)定化系數(shù)為2.57～4.62的過(guò)共析鈦鉻合金經(jīng)過(guò)熔煉后，在隨爐冷卻條件下得到的是單相β-Ti組織；鑄態(tài)合金在700℃保溫退火時(shí)，金屬間化合物TiCr2不僅沿晶界生成并形成連續(xù)分布，還在基體內(nèi)部彌散析出；在隨后的空冷過(guò)程中合金內(nèi)局部發(fā)生β-Ti→α-Ti＋TiCr2共析分解。合金含鉻量越高，在高溫退火時(shí)析出的TiCr2量越多，尺寸越粗大，合金的硬度也越高。電弧熔煉+700℃，20h高溫退火是一種制備含Laves相過(guò)共析鈦鉻合金的可行工藝。
關(guān)鍵字: 鈦鉻合金；共析轉(zhuǎn)變；TiCr2；α-Ti；β-Ti
Ti-Cr alloys with Laves phase TiCr2
GAO Jian-xiang1，ZHU Bao-jun1，QIN Ming-li
（1.State Key Laboratory for Powder Metallurgy，
Central South University，Changsha 410083, China；
2.Automotive and Electromechanical Engineering Department,
Changsha Communications University，Changsha 410076, China；
3.School of Materials Science and Engineering,
University of Science and Techno logy Beijing，
Beijing 100083, China）
Abstract:Hypereutectoid Ti-Cr alloys (18%～30%Cr, mass fraction) with Laves phase Ti Cr2 were prepared by means of non-consumable electrode arc melting and annealing at 700℃ for 2h. The as-cast and as-annealing microstructures were investigated respectively. The results reveal that the microstructure of melted alloy followed by furnace cooling with a stabilization coefficient of 2.77～4.62 are solely composed of β-Ti. Laves phase TiCr2 will be precipitated along the grain boundaries and in the matrix when the alloys are annealed at 700℃, and an eutectoid transformation β-Ti→α-Ti＋TiCr2 happens in some parts of the alloy during air cooling. The higher the chromium content，the more the quantity and the larger the size of TiCr2 and there for e the higher the hardness of the alloy is. Arc melting+700℃, 20h annealing is a feasible process for the preparation of hypereutectoid Ti-Cr alloys with Laves phase TiCr2.
Key words: Ti-Cr alloys；eutectoid transformation；TiCr2； α-Ti；β-Ti
