V85Ti10Y5和V85Ti10Cu5氢分离合金组织与性能研究

Microstructure and properties analysis of hydrogen separation V85Ti10Y5 and V85Ti10Cu5 alloys

摘要:

利用高真空非自耗电弧熔炼炉制备了V85Ti10Y5和V85Ti10Cu5氢分离合金。通过SEM、TEM、XRD、氢渗透实验、PCT吸氢实验、恒压缓冷实验，研究了Y、Cu元素的加入对合金氢渗透性能、氢溶解性能及抗氢脆性能的影响。结果表明:铸态V85Ti10Y5和V85Ti10Cu5合金组织均由V-基体和第二相组成，但前者第二相是弥散分布的富Y颗粒，而后者为既在晶内析出又沿晶界连续分布的铜钛金属间化合物。V85Ti10Y5合金中Y2O3的生成及V85Ti10Cu5合金中部分固溶Cu的斥氢作用和Cu2Ti形成使V中Ti的固溶量减少，进而降低合金中的氢浓度，减小氢固溶产生的内应力，提高抗氢脆性能。V85Ti10Y5和V85Ti10Cu5合金在缓冷过程中均未发生氢脆现象，表现出优异的抗氢脆性能，而且在673 K时的氢渗透率分别为0.139×10-6 mol H2 m-1 s-1 Pa0.5和0.174×10-6 mol H2 m-1 s-1 Pa0.5，是Pd77Ag23氢渗透率的5.5和6.9倍，与商用钯合金相比均展现出较高的渗透率。

Abstract:

Hydrogen separation alloys V85Ti10Y5 and V85Ti10Cu5 were prepared by high vacuum non-consumable arc melting furnace. The effects of the addition of Y and Cu elements on the hydrogen permeability, hydrogen solubility and hydrogen brittleness resistance of the alloy were investigated by SEM, TEM, XRD, hydrogen permeability test, PCT hydrogen absorption test and constant pressure slow cooling test. The results show that the as-cast V85Ti10Y5 and V85Ti10Cu5 alloys are both composed of V-matrix and the second phase, but the second phase of the former is dispersively distributed Y-rich particles, while the latter is a Cu-Ti intermetallic compound precipitated in the grain and distributed continuously along the grain boundary. The formation of Y2O3 in V85Ti10Y5 alloy and the hydrogen-repulsive action of some solid solution Cu in V85Ti10Cu5 alloy and the formation of Cu2Ti reduce the solid solution amount of Ti in V, and then reduce the concentration of hydrogen in the alloy, reduce the internal stress generated by hydrogen solution, improve the anti-hydrogen brittleness. The V85Ti10Y5 and V85Ti10Cu5 alloys showed excellent anti-hydrogen embrittlement properties without hydrogen embrittlement during slow cooling. Moreover, the hydrogen permeability at 673 K is 0.139×10-6 mol H2 m-1 s-1 Pa0.5 and 0.174×10-6 mol H2 m-1 s-1 Pa0.5, which is 5.5 and 6.9 times of Pd77Ag23. Compared with commercial palladium alloys, they all show higher permeability.