發(fā)布時(shí)間：2018-02-16 00:44

  本文關(guān)鍵詞： Ti-Mg合金 生物材料 機(jī)械合金化 放電等離子燒結(jié) 生物活性　出處：《中南大學(xué)》2014年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：鈦及鈦合金具有優(yōu)良的力學(xué)性能和良好的耐腐蝕性,在臨床上長(zhǎng)期被用作人體牙齒和骨頭的替換材料,但其缺乏生物活性。鎂及鎂合金作為生物醫(yī)用材料可在生理環(huán)境中降解,具有良好的生物活性,但其降解過(guò)快易導(dǎo)致植入失效。本文考慮結(jié)合鈦、鎂各自的優(yōu)點(diǎn),嘗試制備一種用于骨組織修復(fù)和替換的新型生物醫(yī)用Ti-Mg合金。 本研究首先通過(guò)機(jī)械合金化方法制備了不同Mg含量的Ti-xMg (x=5,10,15wt.%)合金粉末,然后利用放電等離子燒結(jié)工藝制備了Ti-Mg合金。通過(guò)激光粒度、XRD、SEM、XPS、ICP-AES和力學(xué)性能測(cè)試等手段研究了粉末和合金的相組成、顯微結(jié)構(gòu)和力學(xué)性能,通過(guò)模擬體液浸泡與電化學(xué)測(cè)試研究合金的生物活性和電化學(xué)腐蝕行為。所得結(jié)論如下： 通過(guò)試驗(yàn),確定粉末球磨工藝參數(shù)為：球磨轉(zhuǎn)速240r/min,球料比為10：1,球磨時(shí)間為30h。隨著球磨時(shí)間的延長(zhǎng),Mg逐漸固溶到Ti粉中。隨著Mg含量的增加,混合粉末越難以破碎,Ti-Mg合金粉末的顆粒粒徑隨Mg含量的增加不斷變大。球磨達(dá)到30h時(shí),粉末成分分布均勻,成功實(shí)現(xiàn)合金化。 采用放電等離子燒結(jié)技術(shù),在10KN-800℃條件下制備出了Ti-Mg合金,Ti-5Mg合金的相成分是Ti、一氧化鈦和氧化鎂,Ti-10Mg合金和Ti-15Mg合金相成分為T(mén)i、一氧化鈦、Mg和氧化鎂。SPS制備的Ti-Mg合金組織中存在一定數(shù)量的燒結(jié)殘留孔洞和Mg氣化留下的孔洞。對(duì)燒結(jié)后合金孔隙率和成分進(jìn)行計(jì)算,Ti-5Mg、Ti-10Mg和Ti-15Mg合金致密度依次為99.68%,99.44%和93.49%,致密度隨著Mg含量的增加而降低；燒結(jié)過(guò)程中Ti-5Mg合金Mg未損失,Ti-10Mg和Ti-15Mg合金則損失了3.2.wt.%和5.77.wt.%的Mg。 對(duì)Ti-Mg合金進(jìn)行維氏硬度和抗壓強(qiáng)度測(cè)試,Ti-5Mg和Ti-10Mg的HV5/15硬度值為HV469.28和HV406.69,抗壓強(qiáng)度為1690.89MPa和1671.72MPa,Mg含量增加至15%時(shí),合金硬度顯著降低至HV306.17,抗壓強(qiáng)度降低至1373.06MPa。 模擬體液浸泡實(shí)驗(yàn)表明：Ti-Mg合金在模擬體液中浸泡后,表面均有磷酸鈣鹽沉積,合金中的Mg含量越多,表面沉積的磷酸鈣鹽越多。浸泡過(guò)程中,合金表面Mg2+離子溶解析出,促進(jìn)了溶液中的Ca2+離子和磷酸根離子在合金表面形成磷酸鈣鹽沉積,Mg的加入改善了鈦的生物活性。Ti-Mg合金在模擬體液中的電化學(xué)腐蝕過(guò)程中能夠保持穩(wěn)定性。隨著合金中的Mg含量增加,合金的自腐蝕電位降低,自腐蝕電流增加,合金的耐腐蝕性變差。
[Abstract]:Titanium and titanium alloys have excellent mechanical properties and good corrosion resistance. They have long been used as substitute materials for human teeth and bones in clinic, but they lack biological activity. Magnesium and magnesium alloys can be degraded in physiological environment as biomedical materials. It has good bioactivity, but its degradation is too fast to lead to implant failure. In this paper, considering the advantages of titanium and magnesium, we try to prepare a new biomedical Ti-Mg alloy for bone tissue repair and replacement. In this study, Ti-xMg alloy powder with different mg content was prepared by mechanical alloying. Then the Ti-Mg alloy was prepared by spark plasma sintering. The phase composition, microstructure and mechanical properties of the powder and alloy were studied by means of laser particle size measurement (XRDX) SEMPS ICP-AES and mechanical properties test. The bioactivity and electrochemical corrosion behavior of the alloy were studied by simulated body fluid immersion and electrochemical test. The technological parameters of powder ball milling are determined as follows: ball milling speed 240 r / min, ball / material ratio 10: 1, ball milling time 30 h. With the prolongation of ball milling time, mg is gradually dissolved into Ti powder, and with the increase of mg content, the ball milling process parameters are determined as follows: the ball milling speed is 240 r / min, the ball material ratio is 10: 1 and the milling time is 30 h. The more difficult the mixed powder is, the larger the particle size of Ti-Mg alloy powder is with the increase of mg content. When the powder is milled for 30 h, the composition of the powder is uniformly distributed, and alloying is achieved successfully. Using spark plasma sintering technology, The phase composition of Ti-Mg alloy Ti-5mg was prepared at 10KN-800 鈩，

本文編號(hào)：1514265