Effect of Annealing Temperature on Microstructure and Hardness of Electroformed Ni-W Alloys

The Ni-W alloys were prepared by electroforming method.The alloys samples were annealed at 400～700 ℃,and the Vickers hardness and microstructure of annealed samples were investigated.The results show that the crystal of electroforming alloy is transformed into amorphous structure with the content of W increase.With increasing annealing temperature,the microhardness of the low W content alloy gradually decreases.The hardness of high W content alloys(w(W)35.00%) increases first and decreases afterwards.For the alloy with w(W)=35.35%,Ni4W phase is precipitated.For w(W)=45.52% alloy,the crystallization of amorphous and precipitation of Ni4W phase are evident during annealing.