Segregation defects, known as β-flecks, have long detracted from the widespread use of metastable β-Titanium alloys produced via solidification routes. These defects form when segregated β-stabilising solute such as chromium create localised phase instabilities which is detrimental to the alloy’s aging response and mechanical properties. This work explores whether Additive Manufacturing is a viable process for preventing the formation of these defects in the Beta-C alloy (Ti-3Al-8V-6Cr-4Mo-4Zr). Although it is observed that β-flecks initially form during deposition of the top layer, each new subsequent layer and thermal cycle promotes solid-state diffusion of alloy elements that effectively heals the segregation defect. Additive Manufacturing is thus a promising pathway for producing high quality metastable β-titanium alloys free of this defect.

长期以来，偏析缺陷（称为β斑点）与通过凝固途径生产的亚稳态β钛合金的广泛使用有关。这些缺陷在偏析的β稳定溶质（例如铬）形成局部相不稳定性时形成，这不利于合金的时效响应和机械性能。这项工作探讨了增材制造是否是防止在Beta-C合金（Ti-3Al-8V-6Cr-4Mo-4Zr）中形成这些缺陷的可行方法。尽管观察到在沉积顶层时最初会形成β斑点，但随后的每个新层和热循环都会促进合金元素的固态扩散，从而有效地修复偏析缺陷。因此，增材制造是生产无此缺陷的高质量亚稳态β-钛合金的有前途的途径。