(1. 南昌航空大學(xué) 材料科學(xué)與工程學(xué)院,南昌 330063;
(2. 南京航空航天大學(xué) 材料科學(xué)與技術(shù)學(xué)院,南京 210016;
(3. 北京航空材料研究院,北京 100095)
摘 要: 為研究TB6鈦合金在β相區(qū)熱變形后快冷過程中形變誘導(dǎo)馬氏體的轉(zhuǎn)變行為,采用圓柱試樣在Thermecmaster−Z型熱模擬試驗(yàn)機(jī)上進(jìn)行熱壓縮試驗(yàn),并計(jì)算β相條件下的穩(wěn)定系數(shù),觀察熱變形組織,測(cè)試材料的物相結(jié)構(gòu)。結(jié)果表明:合金β相條件穩(wěn)定下系數(shù)Kβ為1.06,β相處于機(jī)械不穩(wěn)定狀態(tài),在β相區(qū)熱變形后快冷過程中合金存在形變誘導(dǎo)轉(zhuǎn)變斜方馬氏體(α″),β相向斜方馬氏體轉(zhuǎn)變時(shí)3個(gè)點(diǎn)陣方向發(fā)生點(diǎn)陣應(yīng)變?yōu)棣?SUB>1=−7.1%,ε2=7.2%,ε3=1.1%的結(jié)果;形變誘導(dǎo)馬氏體呈現(xiàn)針狀和鋸齒狀兩種形貌,其轉(zhuǎn)變模式是先形成近似平行的細(xì)條狀或針狀主干,后從主干中不斷生長(zhǎng)成樹枝狀,且馬氏體內(nèi)部可能存在孿晶。
關(guān)鍵字: TB6鈦合金;形變誘導(dǎo)馬氏體;穩(wěn)定系數(shù)
(1. School of Material Science and Engineering , Nanchang Hangkong University, Nanchang 330063, China;
2. Institute of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
3. Beijing Institute of Aeronautical Materials, Beijing 100095, China)
Abstract:To study the transformation behavior of deformation-induced martensite in Ti-10Al-2Fe-3V(TB6) alloy during rapid cooling after β hot process,the hot compression experiments adopting cylindrical specimens at constant strain rates were carried out on Thermecmaster−Z simulator. The β stable coefficient (Kβ) of this alloy was calculated and the hot deformation microstructure was observed. The results show that the β stable coefficient (Kβ) is 1.06, the β-phase is of thermomechanical unstability, and the transformation of stress induced orthorhombic martensite from β-phase occurs by transformation strains in three principal lattice directions as ε1=−7.1%, ε2=+7.2%, ε3=+1.1% during rapid cooling after β hot process. The martensite which presents two typical morphologies of transition structure needle-type and serrate-type structure nucleates at pre-existing sub-grain boundaries and grows to laths parallelly.
Key words: TB6 titanium alloy; deformation-induced martensite; stable coefficient


