Zirconium-titanium alloy, its chemical composition (wt %) is: Zr15.5-42.5; Ti50.5-75.5; Al4.5-5.9; V3.0-4.0, the rest are unavoidable impurities contained in raw materials. The preparation method is mainly to put the raw materials into a consumable electric arc furnace, melt them into zirconium alloy ingot, and then through forging, precision forging and annealing, the zirconium titanium base alloy of the invention is obtained. While maintaining the original characteristics of titanium Grade 5, the yield strength, tensile strength and hardness increased by 16.7%, 13.7% and 35% on average, and the alloy has good plastic deformation ability. It not only improves the mechanical properties of the material, but also makes up for the lack of low hardness of the original titanium alloy, and can meet the requirements of material strength and hardness of joint moving parts in aerospace vehicles.
Ductility is the property of any given metal material (i.e., metal and metal alloys). The cold formability of metal materials is based somewhat on near room temperature ductility and the ability of the material to deform without breaking. High strength α-β titanium alloys, such as Ti-6Al-4V alloys, typically have low cold formability at or near room temperature. This limits their acceptance of low temperature processing, such as cold rolling, as these alloys are prone to cracking and fracture when processed at low temperatures. Therefore, because of its limited cold formability at or near room temperature, α-β titanium alloys are usually processed by techniques involving hot processing.
Titanium alloys that exhibit room temperature ductility typically also exhibit relatively low strength. As a result, high-strength alloys typically cost more and have reduced thickness control due to grinding margins. The problem stems from the deformation of the close-packed hexagonal (HCP) crystal structure in these higher strength beta alloys at temperatures below several hundred degrees Celsius.
HCP crystal structures are common for many engineered materials, including magnesium, titanium, zirconium, and cobalt alloys. HCP crystal structures have ABABAB packing order, while other metal alloys, such as stainless steel, brass, nickel, and aluminum alloys, typically have face-centered cube (FCC) crystal structures with ABCABCABC packing order. Due to this difference in stacking order, the number of mathematically possible independent slip systems for HCP metals and alloys is significantly reduced relative to FCC materials. Many independent slip systems in HCP metals and alloys require significantly higher stresses to activate, and these "high resistance" deformation modes are activated only in rare cases. This effect is temperature sensitive, making titanium alloys significantly less malleable at temperatures below a few hundred degrees Celsius.
Combined with the slip system present in HCP materials, many twin systems are possible in non-alloyed HCP metals. The combination of the slip system and the twin system in titanium makes sufficient independent deformation modes possible so that "industrially pure" (CP) titanium can be cold worked at near room temperature (i.e., in the approximate temperature range of -100℃ to +200℃).
