STRAIN AND FRACTURE OF LIQUID-PHASE SINTERED ALLOY 90W-7Ni-3Fe.

It was found that the matrix of the alloy is the first to yield and to undergo plastic deformation. Cracks may be initiated along the W grain/matrix interfaces as the bonding force there is weak. While the bonding force is strengthened to a greater extent than the cleavage failure stress of W, the transgranular cleavage cracking of W grains and the plastic tearing of the matrix may happen simultaneously. Hydrogen is shown as one of the main sources of the interfacial embrittlement of as-sintered specimens. The removal of the hydrogen both stored in the voids and dissolved in metals of the W grain/matrix interfaces is easily done by heat treatment under vacuum.