Development of Titanium Alloys with Low Elastic Modulus and High Corrosion Resistance designed on the Basis of Quantum Chemistry Theory

为开发低弹性模数、高耐蚀性的新型钛合金，制备了含锆量分别为0、20、40、60、70、80、100at.%的钛-锆二元合金，并对其密度、杨氏模量、泊松比和维氏显微硬度进行了研究。初步实验结果如下。纯钛和纯锆二元合金的密度-成分曲线与连接两端两点的直线基线略有正偏差。值得注意的是，与富锆区相比，富钛区偏离直线基线的程度略大。铸态纯钛和纯锆的硬度分别为157VHN和196VHN。在钛中加入20at.%的合金元素可显著提高硬度，说明合金中存在大量的固溶体硬化。在Ti-60at.%Zr成分下，进一步添加Zr可使维氏硬度提高到约370VHN。用钛合金化时，也观察到了类似的固溶硬化现象。然而，与富钛区相比，富锆区硬度的提高幅度要小得多。纯钛的杨氏模数和泊松比显著高于纯锆材。钛与锆合金化后，杨氏模数显著降低，在Ti-60at.%Zr时，杨氏模数最小，约为89 Gpa。另一方面，纯钛的泊松比显著低于纯锆。钛与锆合金化后，泊松比显著增加，在Ti-60at.%Zr时，泊松比达到最大值，约为0.343。

To develop new Ti alloys with low elastic modulus and high corrosion resistance, Ti-Zr binary alloys with Zr content of 0, 20, 40, 60, 70, 80, 100 at.% were prepared and their density, Young's modulus, Poisson's ratio and Vickers microhardness were investigated. Primary experimental results were as follows.1. DensityThe density vs. composition curve for the Ti-Zr binary alloys slightly deviated positively from the straight baseline connecting the two points on both ends for pure Ti and pure Zr. It is noted that the degree of deviation from the straight baseline was slightly greater in the Ti-rich region compared to the Zr-rich region.2. HardnessHardness of the as-cast pure Ti and Zr were 157 VHN and 196 VHN, respectively. The alloying addition of 20 at.% Zr to Ti drastically increased hardness, indicating that a great deal of solid solution hardening occurred. Further addition of Zr further increased Vickers hardness up to about 370 VHN at Ti-60 at.% Zr composition. Similar solid solution hardening was observed when Zr was alloyed with Ti. However, magnitude of increase in hardness was much weaker in the Zr-rich region compared to the Ti-rich region.3. Young's modulus and Poisson's ratioYoung's modulus of pure Ti was significantly higher than that of pure Zr. By alloying Ti with Zr, Young's modulus markedly decreased and the minimum Young's modulus of about 89 GPa was obtained at the Ti-60 at.% Zr composition. On the other hand, Poisson's ratio of pure Ti was significantly lower than that of pure Zr. By alloying Ti with Zr, Poisson's ratio markedly increased and the maximum Poisson's ratio of about 0.343 was obtained at the Ti-60 at.% Zr composition.