Relationship between Intragranular α Phase Width and Microhardness of TC18 Titanium Alloy

Four typical microstructures of TC18 titanium alloy (Widmannstatten structure, Fine basketweave structure, Bi-model structure, Coarse basketweave structure) were investigated, including the changes of intragranular α phase width and the relationship between intragranular α phase width and microhardness. The results show that the intragranular α phase width of the four typical microstructures varies greatly in accordance with the order from smallest to largest: Widmannstatten structure < Fine basketweave structure < Bi-model structure < Coarse basketweave structure. The microhardness of the TC18 titanium alloy reduces with the increase of intragranular α phase width.