Phase transformation and damping behavior of lightweight porous TiNiCu alloys fabricated by powder metallurgy process

粉末冶金法制备轻质多孔TiNiCu形状记忆合金的相变和阻尼行为(英文)

Porous TiNiCu ternary shape memory alloys （SMAs） were successfully fabricated by powder metallurgy method. The microstructure, martensitic transformation behavior, damping performance and mechanical properties of the fabricated alloys were intensively studied. It is found that the apparent density of alloys decreases with increasing the Cu content, the porous Ti50Ni40Cu10 alloy exhibits wide endothermic and exothermic peaks arisen from the hysteresis of martensitic transformations, while the porous Ti50Ni30Cu20 alloy shows much stronger and narrower endothermic and exothermic peaks owing to the B2-B19 transformation taking place easily. Moreover, the porous Ti50Ni40Cu10 alloy shows a lower shape recovery rate than the porous Ti50Ni50 alloy, while the porous Ti50Ni30Cu20 alloy behaves reversely. In addition, the damping capacity （or internal friction, IF） of the porous TiNiCu alloys increases with increasing the Cu content. The porous Ti50Ni30Cu20 alloy has very high equivalent internal friction, with the maximum equivalent internal friction value five times higher than that of the porous Ti50Ni50 alloy.

利用梯级粉末烧结法成功制备出轻质高阻尼的多孔TiNiCu形状记忆合金,并对其组织、相变行为、阻尼性能以及力学性能进行深入研究。研究发现,所制备的多孔TiNiCu合金的表观密度随着Cu含量的增加而降低;在降温和升温过程中,由于多孔Ti50Ni40Cu10合金基体中相变的滞后和叠加而使其相变温度区间宽化,相变峰弱化;而多孔Ti50Ni30Cu20合金基体中发生B2-B19相变而使其具有窄的相变温度区间以及较高的相变峰;多孔Ti50Ni40Cu10合金的形状回复率低于多孔Ti50Ni50合金的,而多孔Ti50Ni30Cu20合金的形状回复率则高于多孔Ti50Ni50合金的。研究还表明,多孔TiNiCu合金的内耗值随着Cu含量的增加而增大,其中多孔Ti50Ni30Cu20合金的一个显著特性是具有很高的等效内耗,其最大等效内耗值是多孔Ti50Ni50合金的5倍。