Crack suppression via in-situ oxidation in additively manufactured W-Ta alloy

Laser Powder Bed Fusion of Unalloyed Tungsten: A Review of Process, Structure, and Properties Relationships

“…The addition of such phases has been widely used in powder metallurgy as a method for grain size refinement, oxidation restraining, and dislocation mobility improvement. Attempts to add small amounts (<6%wt) of tantalum and titanium as well as nano ZrC and Y 2 O 3 have shown promising results in terms of crack suppression and grain refinement in tungsten produced by LPBF [33,[80][81][82][83][84]. The underlying mechanisms by which such additions can change the produced microstructure/properties are however out of the scope of this review and have been discussed in a review by Li et al [23].…”

Influence of Cr3C2 Additions to AISI H13 Tool Steel in the LPBF Process

“…[14] Known routes for hot crack elimination are: alloy modification, process modification, post-processing, e.g., hot isostatic pressing. [9] In this study, the approach of alloy modification is chosen to reduce the hot cracking tendency of AISI H13 hot work tool steel.Li et al [10] observed a reduced cracking tendency in W alloy with Ta additives. The in situ oxidation of Ta leads to the formation of primary oxides which can act as heterogeneous nucleation sites for solidification.…”

“…Li et al [10] observed a reduced cracking tendency in W alloy with Ta additives. The in situ oxidation of Ta leads to the formation of primary oxides which can act as heterogeneous nucleation sites for solidification.…”

“…The amount of nonbond fine powder can be reduced by ball milling of 3 h and more. Ball milling is accompanied by plastic deformation of the base powder leading to variations from the original spherical shape.Hot cracks are a known phenomenon in additive manufacturing (AM), which were observed by various researchers for different alloys: nickel-based materials, [8,9] tungsten, [10] aluminum-based alloys, [11] and steels. [12] Hot cracks form during solidification as the residual melt is trapped between solidified grains/dendrites and the melt flow in the interdendritic space is hindered.…”

“…Hot cracks are a known phenomenon in additive manufacturing (AM), which were observed by various researchers for different alloys: nickel-based materials, [8,9] tungsten, [10] aluminum-based alloys, [11] and steels. [12] Hot cracks form during solidification as the residual melt is trapped between solidified grains/dendrites and the melt flow in the interdendritic space is hindered.…”