粉末冶金醫(yī)用超細(xì)晶β型Ti28Nb2Zr8Sn合金的顯微組織與力學(xué)性能
發(fā)布時(shí)間:2018-06-09 14:11
本文選題:粉末冶金 + β型-Ti合金 ; 參考:《稀有金屬材料與工程》2017年03期
【摘要】:采用機(jī)械球磨+放電等離子燒結(jié)的方法制備出高強(qiáng)度低模量的超細(xì)晶β型Ti28Nb2Zr8Sn合金。XRD和SEM結(jié)果表明,60 h球磨后的終態(tài)合金粉末經(jīng)放電等離子燒結(jié)后,獲得的超細(xì)晶塊體合金為完全的bcc結(jié)構(gòu);TEM分析表明,超細(xì)晶塊體合金中bcc結(jié)構(gòu)的β-Ti晶粒為等軸狀,其尺寸為500~1000 nm,遠(yuǎn)小于鑄造法制備同類合金幾十微米的晶粒尺寸;力學(xué)性能測(cè)試表明,隨升溫速率增大或保溫時(shí)間縮短,超細(xì)晶塊體合金的抗壓縮強(qiáng)度逐漸增大,彈性模量逐漸減小。在燒結(jié)溫度為900℃、升溫速率為150℃/min且保溫時(shí)間為0 min的條件下,得到的超細(xì)晶塊體合金晶粒最細(xì)小,其壓縮強(qiáng)度達(dá)到最大(2675 MPa),對(duì)應(yīng)的斷裂應(yīng)變也最大(0.54),且其彈性模量最低(31.6 GPa);同時(shí),該合金試樣的加工硬化指數(shù)0.073遠(yuǎn)高于Ti6Al4V合金,這說明其加工硬化和塑性變形能力遠(yuǎn)遠(yuǎn)優(yōu)于Ti-6Al-4V合金,故能夠承受更大的載荷和經(jīng)歷更大的變形,可作為一種優(yōu)異的生物醫(yī)用候選材料。
[Abstract]:Ultrafine 尾 -type Ti28Nb2Zr8Sn alloy with high strength and low modulus was prepared by mechanical ball milling spark plasma sintering. The results of XRD and SEM showed that the final alloy powder after 60 h ball milling was sintered by spark plasma. Tem analysis shows that the 尾 -Ti grains of the bcc structure in the ultrafine crystal bulk alloy are equiaxed, and the size is 500 ~ 1000nm, which is much smaller than the grain size of dozens of microns of the same alloy prepared by casting method. The mechanical properties test showed that the compressive strength and elastic modulus of the superfine bulk alloy increased gradually with the increase of the heating rate or the shortening of the holding time. When the sintering temperature is 900 鈩,
本文編號(hào):1999998
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