Metal additive manufacturing (AM) is well known for its unprecedented geometric freedom through near-net-shape production. Here, we show that the AM route is not limited to fabricating bulk alloys, but can also be used to tune the microstructure and properties of the surface through melting an additional metal atop, which interdiffuses with the base AM block to achieve intimate alloying. As a model demonstration, we demonstrate surface cladding using laser powder-bed-fusion (LPBF) as a supplementary step to complement AM, implemented by melting V powders to metallurgically react with and strengthen the AM-printed Ti-Nb base alloy. The resultant surface cladding is extraordinarily strong with no flaws nor weak interface. The cladding/matrix composite exhibits enhanced yield strength without compromising the tensile ductility of the base alloy. The cladding also offers significantly enhanced hardness and wear resistance. This finding adds an innovative twist for AM in the realm of high-performance alloy fabrication.

Link:Laser-fusion-alloyed hard surface cladding as a complementary step to additive manufacturing - ScienceDirect