微結(jié)構(gòu)和應(yīng)力比對Ti-6Al-4V合金高周和超高周疲勞行為的影響
發(fā)布人：上海艾荔艾合金股份有限公司www.shailiai.cn
更新時間：2016-05-04
采用旋轉(zhuǎn)彎曲和超聲疲勞實(shí)驗(yàn)分別測試了全等軸和等軸雙態(tài)組織 Ti-6Al-4V 的高周和超高周疲勞性能, 并用 SEM 觀察了疲勞斷口特征.
微結(jié)構(gòu)和應(yīng)力比對Ti-6Al-4V合金高周和超高周疲勞行為的影響EFFECTS OF MICROSTRUCTURE AND STRESS RATIO ON?HIGH-CYCLE AND VERY-HIGH-CYCLE FATIGUE BEHAVIOR?OF Ti-6Al-4V ALLOY采用旋轉(zhuǎn)彎曲和超聲疲勞實(shí)驗(yàn)分別測試了全等軸和等軸雙態(tài)組織 Ti-6Al-4V 的高周和超高周疲勞性能, 并用 SEM 觀察了疲勞斷口特征. 結(jié)果表明: 2 種組織 Ti-6Al-4V 合金的高周和超高周疲勞行為相似, 不同應(yīng)力比下, 其S-N 曲線均表現(xiàn)出單線形或雙線形的形式; 存在滑移機(jī)制和解理機(jī)制2 種疲勞破壞機(jī)制. 隨應(yīng)力比增加, 2種組織Ti-6Al-4V合金的高周和超高周疲勞破壞機(jī)制均從滑移機(jī)制向解理機(jī)制轉(zhuǎn)變. 基于疲勞壽命和疲勞強(qiáng)度模型分析了應(yīng)力比對 2 種機(jī)制之間競爭行為的影響, 模型結(jié)果與實(shí)驗(yàn)結(jié)果趨勢吻合.?
Titanium alloys have been widely used as superior engineering materials because of?their high specific strength, high temperature resistance and high corrosion resistance. In their?engineering applications such as used in aircraft engines, titanium alloys may experience even 1010?fatigue cycles. Recently, faceted crack initiation was observed in high-cycle fatigue (HCF) and?very-high-cycle fatigue (VHCF) regimes of titanium alloys, which resulted in a sharp decrease in?fatigue strength. Therefore, the HCF and VHCF of titanium alloys have both scientific significance?and engineering requirement. In this work, the effects of microstructure and stress ratio (R) on HCF?and VHCF of a Ti-6Al-4V alloy have been investigated. Fatigue tests were conducted on a?rotating-bending fatigue machine and an ultrasonic fatigue machine. All the fatigue fracture?surfaces were observed by SEM. The results show that the HCF and VHCF behaviors of the?fully-equiaxed and the bimodal Ti-6Al-4V alloy are similar. The observations of fracture surface?indicate that two crack initiation mechanisms prevail, i.e. slip mechanism and cleavage mechanism.?With the increase of stress ratio, the crack initiation mechanism switches from slip to cleavage. The?S-N curves present the single-line type or the bilinear type. For the cases of rotating-bending and?ultrasonic axial cycling with R=?1, ?0.5 and 0.5, the S-N curves are single-line type corresponding?to the slip mechanism or cleavage mechanism. For thecases of R=?0.1 and 0.1, the S-N curves are?bilinear type corresponding to both slip and cleavage mechanisms. A model based on fatigue life?and fatigue limit is proposed to describe the competition between the two mechanisms, which is in?agreement with the experimental results.?
作為值得信賴的合作伙伴和高品質(zhì)金屬合金的半成品供應(yīng)商，艾荔艾擁有完善的服務(wù)體系和專業(yè)的團(tuán)隊。在同客戶交易的過程中，我們力求根據(jù)不同的應(yīng)用需求將我們的產(chǎn)品做到精益求精。針對當(dāng)前和未來的市場需求，艾荔艾致力于為客戶提供最佳的金屬材料解決方案。
AILIAI has been a reliable partner and supplier of sophisticated and high-quality semi-finished products maed of alloys. In dialogue with our customers, we optimise our products to meet the specific application requirements. AILIAI develops the best alloy material solutions for current and future challenges.
獲取更多我們供應(yīng)的合金和服務(wù)信息，請致電086-021-67660801或發(fā)電子郵件[email protected]聯(lián)系我們，您也可以通過微博，微信，領(lǐng)英，XING，臉書和推特與我們互動。
For more information on the alloys and services that we supply,?call us?at 086-021-67660801 or email us at [email protected]. You can also get in touch on social media, we are constantly active on?Weibo,?Weixin,?LinkedIn,?XING, Facebook?and?Twitter.