退火对海绵钛/电解钛熔炼TC4合金铸锭轧制板材组织性能的影响

以海绵钛和电解钛分别作为熔炼TC4钛合金的原材料,将熔炼后的铸锭进行热轧并退火处理,研究不同原料铸锭轧制的TC4合金板材退火处理后的组织与力学性能。结果表明:去应力退火对电解钛与海绵钛TC4合金板材组织的影响不大。再结晶退火后,电解钛与海绵钛TC4合金板材均有再结晶的等轴α相,而电解钛TC4合金的等轴化程度更高,内部组织更均匀。海绵钛TC4合金板材在经550 ℃退火处理后的应力去除效果比电解钛TC4合金的好,其强度略微降低,而塑性提升更为明显。电解钛TC4合金板材在经过800 ℃退火处理后的再结晶效果比海绵钛TC4合金好,其强度略微降低,而塑性得到极大的提升。两种钛合金板材退火后板材的断裂方式皆为韧性断裂。海绵钛TC4合金板材经退火后硬度降低,而电解钛TC4合金板材经退火后硬度增加。

Effect of annealing on microstructure and properties of TC4 alloy rolled sheet made from sponge titanium/electrolytic titanium

Sponge titanium and electrolytic titanium were used as raw materials for making TC4 titanium alloy. The smelted ingot was hot rolled and annealed to study the microstructure and mechanical properties after different raw material ingot rolling. The results show that the stress relief annealing has little effect on the microstructure of electrolytic titanium and titanium sponge TC4 alloy sheet. After recrystallization annealing, both the electrolytic titanium and the sponge titanium TC4 alloy plate have recrystallized, producing equiaxed α phase, while the electrolytic titanium TC4 alloy has a higher degree of equiaxification and a more uniform internal structure. The stress relief effect of the sponge titanium TC4 alloy sheet after annealing at 550 ℃ is better than that of the electrolytic titanium TC4 alloy, and its strength is slightly reduced, but the improvement of plasticity is more obvious. The recrystallization effect of electrolytic titanium TC4 alloy plate after annealing at 800 ℃ is better than that of sponge titanium TC4 alloy, its strength is slightly reduced, but the plasticity is greatly improved. The fracture mode of the two titanium alloy sheets after annealing is all ductile fracture. The hardness of the sponge titanium TC4 alloy plate is reduced after annealing, but the hardness of the electrolytic titanium TC4 alloy plate is increased after annealing.