高钨含量钽基合金力学性能的研究

Study on Mechanical Properties of Several Tantalum Alloys with Higher Tungsten Content

Ｔａ－１０Ｗ、Ｔａ－１２Ｗ、Ｔａ－１３Ｗ和Ｔａ－１５Ｗ４种Ｔａ－Ｗ二元合金经电子束熔炼，最终轧制成７．０ｍｍ和１．０ｍｍ厚的板材，并经再结晶热处理。室温力学性能试验表明，合金强度和硬度随Ｗ含量增加线性增长，合金延性随Ｗ含量增加下降不显著，意味着几种高Ｗ含量的Ｔａ－Ｗ合金既有高强度，又有良好的塑性。合金强度与硬度之间亦有线性关系，遵从ｂｃｃ金属的绝热固溶强化模型，但高Ｗ含量合金的实测硬度低于模型计算硬度值，说明合金仍可进行冷加工。在同样条件下，几种合金同纯Ｔａ相比有均匀的显微组织，保证了合金有良好的韧性。对合金的强化机制也作了一定的讨论。

Ta-(10～15)W alloys were melted by electron beam furnace, upset-forged and rolled to the final plates of 7.0mm and 1.0mm in thickness. Each of the samples for property measurements was annealed to obtain a fully recrystallized microstructure. The property measurements at the room temperature show that the strength and hardness of alloys increase linearly with the tungsten content in alloys, but the ductility of these alloys does not change strikingly. Taking the advantage of the strengthening effect of W for Ta, the Ta-W binary alloys with a higher intensty and excellent ductility would be obtained. There exists a linear relation between the strength and vickers hardness in Ta-(10～15)W alloys. These alloys also obey the athermal solid solution hardening mechanism. However, the measured hardness values of these alloys at the room temperature are less than the calculated values based on the model, which indicates that the Ta-W alloys with 15at% W are also able to cold-roll. The present several Ta-W alloys exhibit an uniform recrystallized microstructure, which would ensure these alloys to possess an excellent ductility and toughness.