The Influence Of Alloying Elements On The Mechanical Properties Of Titanium

The main strengthening methods of titanium alloys are solid solution strengthening and dispersion strengthening. The former is to improve the properties of the alloy by increasing the solid solution solubility of the α and β phases, and the latter is to obtain highly dispersed α+β or α+ intermetallic compounds through heat treatment to achieve the purpose of strengthening. Titanium alloy: It is difficult to adjust the structure, and while meeting the high strength level, it still maintains sufficient plasticity and toughness. Among the α stabilizing elements, Al has the most significant solid solution strengthening effect. β-stabilizing elements are preferentially dissolved in β-phase, so β-phase has stronger strength and hardness. The average strength of the alloy increases as the proportion of β-phase in the structure increases. When α-phase and β-phase each account for 50%, the strength reaches its peak , Continue to increase the number of β phases, but the intensity decreases. For heat-resistant alloys that are used for a long time at high temperatures, the presence of inactive eutectoid elements will reduce the thermal stability of the material. When approaching the phase transition temperature, the stability of the tissue decreases and the atomic activity increases, which promotes the softening of the metal. Therefore, the composition of heat-resistant titanium alloys should be mainly α-stabilizing elements and neutral elements. As for β-stabilizing elements, the effect is generally poor. Only those elements such as molybdenum and tungsten, which can strongly improve the bonding force of titanium atoms, and silicon and copper with higher eutectoid transformation, can effectively increase the thermal strength of the alloy within the appropriate solubility range. The heat-resistant titanium alloy should be single-phase structure, generally α-type or near-α-type alloys are used as materials for high temperature work.