本文關(guān)鍵詞：TNW700高溫鈦合金板材超塑變形行為研究　出處：《稀有金屬》2016年01期 　論文類(lèi)型：期刊論文

  更多相關(guān)文章： TNW鈦合金 超塑性 本構(gòu)方程 顯微組織

【摘要】：TNW700鈦合金是我國(guó)自主研發(fā)的近α型、可在700℃短時(shí)使用的高溫鈦合金。針對(duì)TNW700合金板材在溫度為890~950℃、恒應(yīng)變速率為0.0100~0.0005 s~(-1)下的單向超塑拉伸變形行為進(jìn)行了研究,利用Zener-Hollomn參數(shù)和Arrhenius方程建立了TNW700鈦合金的峰值應(yīng)力本構(gòu)方程。結(jié)果表明:TNW700鈦合金的超塑性變形行為與普通鈦合金不同,其加工硬化階段較長(zhǎng),且溫度越高、應(yīng)變速率越低,動(dòng)態(tài)硬化的效果更加明顯,遠(yuǎn)高于再結(jié)晶軟化程度,晶粒尺寸的增加是導(dǎo)致加工硬化的主要原因。在950℃,0.0005 s~(-1)條件下獲得的最大延伸率為933%。所建立的峰值應(yīng)力方程為σ_p=17.414[1.047(lnε+540210/RT)-46.587],其變形激活能Q=540.21 k J·mol~(-1)。在較低溫度條件下變形,在斷口附近由于應(yīng)變速率高和變形溫度低的雙重作用在晶界三角區(qū)產(chǎn)生應(yīng)力集中使晶界滑移變得困難而導(dǎo)致有孔洞產(chǎn)生。隨著變形溫度的升高,β相含量和尺寸逐漸增加,高溫、高應(yīng)變速率條件下有次生α相析出,采用電子探針?lè)治?EPMA)發(fā)現(xiàn)β晶粒微區(qū)成分的變化是次生α相產(chǎn)生的主要原因。
[Abstract]:TNW700 titanium alloy is near a type developed in China, can be in high temperature titanium alloy 700 degrees. For short time use of TNW700 alloy sheet at a temperature of 890~950, the constant strain rate of 0.0100~0.0005 s~ (-1) under unidirectional superplastic tensile deformation behavior of TNW700 titanium alloy, the peak stress of the constitutive equation is established by using the Zener-Hollomn parameter and Arrhenius equation. The results show that the Superplasticity of TNW700 titanium alloy with ordinary titanium alloy with different deformation behavior, the hardening stage is longer, and the higher the temperature is, the lower the strain rate, dynamic hardening effect is more obvious, far higher than the recrystallization softening, the increase of the grain size is the main the cause of hardening. At 950 degrees, 0.0005 s~ (-1) under the condition of the maximum elongation rate was 933%. the peak stress equation for sigma _p=17.414[1.047 (LN e +540210/RT) -46.587], and the deformation activation energy Q=540. 21 K J mol~ (-1). The deformation at lower temperatures, in the vicinity of the fracture surface due to the high strain rate and deformation temperature and low stress concentration due to the dual role of grain boundary sliding becomes difficult due to the emergence of holes in the grain boundary triangle. With the increase of deformation temperature, phase content and size increased gradually, high temperature, high strain rate under the condition of a secondary phase precipitates by electron probe microanalysis (EPMA) found that changes in beta grain micro area composition is the main reason of secondary phase.

【作者單位】： 北京航空制造工程研究所金屬成形技術(shù)研究室塑性成形技術(shù)航空科技重點(diǎn)實(shí)驗(yàn)室數(shù)字化塑性成形技術(shù)與裝備北京市重點(diǎn)實(shí)驗(yàn)室;中國(guó)科學(xué)院金屬研究所鈦合金研究部;
【基金】：國(guó)家自然科學(xué)基金項(xiàng)目(51405458) 航空研究項(xiàng)目(61901110301)資助
【分類(lèi)號(hào)】：TG146.23
【正文快照】： 高溫鈦合金的研制一直是在先進(jìn)航空發(fā)動(dòng)機(jī)需求的牽引下進(jìn)行,主要用于飛機(jī)發(fā)動(dòng)機(jī)的壓氣機(jī)盤(pán)、葉片和機(jī)匣等[1-2],旨在代替比重和成本更高的高溫合金,因此高溫鈦合金的發(fā)展對(duì)高性能航空發(fā)動(dòng)機(jī)具有重要意義。目前,國(guó)內(nèi)外對(duì)600℃及以上的高溫鈦合金研制極為活躍,如美國(guó)的Ti1100、，

本文編號(hào)：1433309