Grain boundary of α phase damaged ductility of laser melting-deposited TC18 titanium alloy and grain boundary of α phases were difficult to break by nominal heat treatment. An extra thermal deformation was introduced to break the grain boundary of α phase with the improved mechanical property of TC18 titanium alloy fabricated by laser melting deposition technique. Results indicated that after thermal deformation, β grains in alloy seriously elongated. When sample was deformed at temperatures from 750 to 850 °C, α phase exhibited both rod and irregular morphologies with discontinuous distribution at grain boundary, and the subsequent heat treatment would lead to spheroidization of the α phase. However, after deformation at 900 °C, α phase transferred into β phase and the subsequent heat treatment would make continuous grain boundary of α phase reappear. The suitable hot deformation can effectively break the continuous grain boundary in laser melting-deposited TC18 alloy with respected improved ductility.

α相的晶界破坏了激光熔融沉积的TC18钛合金的延展性，并且α相的晶界难以通过标称热处理而破坏。通过激光熔融沉积技术制备的TC18钛合金具有改善的机械性能，引入了额外的热变形以破坏α相的晶界。结果表明，热变形后，合金中的β晶粒严重拉长。当样品在750至850°C的温度下变形时，α相既呈棒状又呈不规则形貌，在晶界处分布不连续，随后的热处理将导致α相发生球化。但是，在900°C下变形后，α相转变为β相，然后进行热处理，将使α相的连续晶界重新出现。适当的热变形可以有效地打破激光熔融沉积TC18合金中的连续晶界，同时提高了延展性。