發(fā)布時間：2019-05-19 20:02

【摘要】：從20世紀中葉以來,以鈦及鈦合金為主的生物醫(yī)用材料開始廣泛應用于人體失效的硬組織替換,并在之后的研發(fā)、應用中取得了突破性進展,極大的提高了人們的生存質(zhì)量。生物醫(yī)用鈦合金由于其彈性模量低、強度高、生物相容性好、比強度大、耐蝕性能優(yōu)異等特點,成為人體醫(yī)用植入產(chǎn)品的首選材料。本課題以團簇模型理論作為研究基礎(chǔ),用CN14團簇模型表示體心立方結(jié)構(gòu)β-Ti合金的成分式,根據(jù)團簇內(nèi)各合金化元素間的混合焓△H大小(△H用于團簇內(nèi)部表征原子間的相互作用力的大小,△H越負相互吸引力越大,△H越正相互排斥力越大),并在電子濃度e/a=4.17的約束下,從理論上確定以Sn充當中心原子、Ti為殼層原子、Nb為連接原子的“團簇+連接原子”模型[SnTi14]Nb3.用真空電弧熔煉爐將原料熔煉成Φ30mm,高10mm鈕扣狀合金鑄錠,經(jīng)過成分分析、金相觀察、XRD測試和納米壓痕測試等測試方法的檢測。我們的實驗主要分為三個階段,第一階段利用Zr原子取代中心原子Sn,團簇的實際表達式為[(Sn1-Tix)(Ti14-xZrx)]Nb3(x=0.0.3、0.5、0.7);第二階段在[SnTi14]Nb3的基礎(chǔ)上逐步減少Sn元素含量,得到[Sn1-xTi14+x]Nb3(x=O.O.1、0.2、0.3、0.4)的團簇式；第三階段是在第二階段減少三元合金中Sn含量的基礎(chǔ)上,加入Zr原子進行合金化,使之取代團簇殼層上的Ti原子,成分式為[(SnxTi1-x) (Ti14-yZry)]Nb3(X由三元合金確定,Y=0.2、0.4、0.6、0.8)。實驗驗證了在鈦合金中團簇模型應用的可行性,證明了團簇結(jié)構(gòu)與合金相組織之間存在一定聯(lián)系,隨著團簇內(nèi)部混合焓降低,鈦合金的β相穩(wěn)定性也隨之下降合金由β相向α相過渡。在三個階段的試驗中,三元合金[Sn0.8Ti14.2]Nb3的彈性模量(65.6 GPa)和硬度(959.3HV)最低,此時合金由α”+β相共同組成。在三元合金基礎(chǔ)上添加Zr元素的[(SnxTi1-x)(Ti14-yZry)]Nb3系列合金中,隨著Zr原子的增多,彈性模量逐漸增大,Zr原子的加入增加了合金的β相穩(wěn)定能力,此時的Zr元素不再為中性元素,而是作為β相穩(wěn)定元素。并且Zr原子的加入會增加合金的硬度。
[Abstract]:Since the middle of the 20th century, biomedical materials dominated by titanium and titanium alloys have been widely used in the replacement of hard tissue with human failure. After that, breakthrough progress has been made in the development and application of titanium and titanium alloys, which has greatly improved the quality of life of people. Biomedical titanium alloy has become the first choice for human medical implantation products because of its low elastic modulus, high strength, good biocompatibility, high specific strength and excellent corrosion resistance. In this paper, based on the cluster model theory, the CN14 cluster model is used to represent the composition of body-centered cubic 尾-Ti alloy. According to the mixing enthalpy H between the alloyed elements in the cluster (H is used to characterize the interaction force between atoms in the cluster, the more negative mutual attraction of H is, the greater the positive mutual repulsive force of H is). Under the constraint of electron concentration e/a=4.17, the "cluster connected atom" model [SnTi14] Nb3. with Sn as the central atom, Ti as the shell atom and Nb as the connecting atom is determined theoretically. The raw materials were melted into 桅 30mm, high 10mm button alloy ingots in vacuum arc melting furnace. The test methods were analyzed by composition analysis, metallographic observation, XRD test and nano indentation test. Our experiment is mainly divided into three stages. In the first stage, the actual expression of replacing the central atom Sn, cluster with Zr atom is [(Sn1-Tix) (Ti14-xZrx)] Nb3 (x 鈮，

本文編號：2481029