(北京有色金屬研究總院 有色金屬材料制備加工國家重點(diǎn)實(shí)驗(yàn)室，北京100088)
摘 要: 利用XRD、OM、SEM和TEM等技術(shù)研究固溶溫度和冷卻速度對Ti-3.0Al-2.3Cr-1.3Fe鈦合金的顯微組織及力學(xué)性能的影響。結(jié)果表明：該合金經(jīng)過960 ℃固溶處理，水淬(WQ)后的組織主要由α′馬氏體和β相組成，空冷(AC)后的組織主要由α相和殘留β基體組成，爐冷(FC)后的組織為網(wǎng)籃組織，主要由大量集束α相及少量β相組成。空冷時(shí)隨著熱處理溫度的升高，初生α相逐漸轉(zhuǎn)變?yōu)棣孪啵恢箅S著溫度的升高，β晶粒長大。該合金的強(qiáng)度隨著冷卻速度的增加而增加，WQ后的強(qiáng)度最大，抗拉強(qiáng)度和屈服強(qiáng)度分別達(dá)到1 270和1 160 Mpa；AC后，斷面收縮率最高為40%左右，而伸長率隨冷卻速度增加而降低。通過觀察拉伸斷口的SEM形貌發(fā)現(xiàn)，該合金在FC和AC后所表現(xiàn)出的斷裂方式以韌性為主，WQ后的斷裂以脆性斷裂為主。
關(guān)鍵字: Ti-3.0Al-2.3Cr-1.3Fe；固溶；顯微組織；力學(xué)性能
（State Key Laboratory of Nonferrous Metals and Processes,
General Research Institute for Nonferrous Metals, Beijing 100088, China）
Abstract:The effects solution temperature and cooling rate on the microstructure and mechanical properties of Ti-3.0Al-2.3Cr-1.3Fe titanium alloy were studied by means of XRD, OM, SEM and TEM. The results indicate that the microstructure of the alloy after water quenching consists of α′ martensite and metastable β phase, those after air cooling consists of α phase and residual β phase, and those after furnace cooling is typical basketweave microstructure which consists of colony α phase and little β phase. The primary α turns to β phase with temperature increasing, and then the β grain grows bigger when the temperature is above the phase transformation temperature. The strength of this alloy increases with the cooling rate increasing, after water quenching, the tensile strength and yield strength reach to 1 270 and 1 160 MPa, respectively. The reduction of area is nearly 40% after air cooling, the elongation decreases with the cooling rate increasing. Through observation of the fracture SEM morphology, the fracture way is toughness fracture after air cooling and furnace cooling, and is brittle fracture after water quenching.
Key words: Ti-3.0Al-2.3Cr-1.3Fe; solution; microstructure; mechanical properties
