新型生物医用Ti-Mg合金的制备及组织与性能研究

发布时间：2018-02-16 00:44

  本文关键词： Ti-Mg合金 生物材料 机械合金化 放电等离子烧结 生物活性　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：钛及钛合金具有优良的力学性能和良好的耐腐蚀性,在临床上长期被用作人体牙齿和骨头的替换材料,但其缺乏生物活性。镁及镁合金作为生物医用材料可在生理环境中降解,具有良好的生物活性,但其降解过快易导致植入失效。本文考虑结合钛、镁各自的优点,尝试制备一种用于骨组织修复和替换的新型生物医用Ti-Mg合金。 本研究首先通过机械合金化方法制备了不同Mg含量的Ti-xMg (x=5,10,15wt.%)合金粉末,然后利用放电等离子烧结工艺制备了Ti-Mg合金。通过激光粒度、XRD、SEM、XPS、ICP-AES和力学性能测试等手段研究了粉末和合金的相组成、显微结构和力学性能,通过模拟体液浸泡与电化学测试研究合金的生物活性和电化学腐蚀行为。所得结论如下： 通过试验,确定粉末球磨工艺参数为：球磨转速240r/min,球料比为10：1,球磨时间为30h。随着球磨时间的延长,Mg逐渐固溶到Ti粉中。随着Mg含量的增加,混合粉末越难以破碎,Ti-Mg合金粉末的颗粒粒径随Mg含量的增加不断变大。球磨达到30h时,粉末成分分布均匀,成功实现合金化。 采用放电等离子烧结技术,在10KN-800℃条件下制备出了Ti-Mg合金,Ti-5Mg合金的相成分是Ti、一氧化钛和氧化镁,Ti-10Mg合金和Ti-15Mg合金相成分为Ti、一氧化钛、Mg和氧化镁。SPS制备的Ti-Mg合金组织中存在一定数量的烧结残留孔洞和Mg气化留下的孔洞。对烧结后合金孔隙率和成分进行计算,Ti-5Mg、Ti-10Mg和Ti-15Mg合金致密度依次为99.68%,99.44%和93.49%,致密度随着Mg含量的增加而降低；烧结过程中Ti-5Mg合金Mg未损失,Ti-10Mg和Ti-15Mg合金则损失了3.2.wt.%和5.77.wt.%的Mg。 对Ti-Mg合金进行维氏硬度和抗压强度测试,Ti-5Mg和Ti-10Mg的HV5/15硬度值为HV469.28和HV406.69,抗压强度为1690.89MPa和1671.72MPa,Mg含量增加至15%时,合金硬度显著降低至HV306.17,抗压强度降低至1373.06MPa。 模拟体液浸泡实验表明：Ti-Mg合金在模拟体液中浸泡后,表面均有磷酸钙盐沉积,合金中的Mg含量越多,表面沉积的磷酸钙盐越多。浸泡过程中,合金表面Mg2+离子溶解析出,促进了溶液中的Ca2+离子和磷酸根离子在合金表面形成磷酸钙盐沉积,Mg的加入改善了钛的生物活性。Ti-Mg合金在模拟体液中的电化学腐蚀过程中能够保持稳定性。随着合金中的Mg含量增加,合金的自腐蚀电位降低,自腐蚀电流增加,合金的耐腐蚀性变差。
[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，

本文编号：1514265