Liquid and Solid Metal Embrittlement

Liquid metal embrittlement (LME) is a brittle fracture of a normally ductile metal when in contact with a liquid metal and stressed in tension. There is no change in the yield behavior of the metal; however, fracture can occur well below the metal’s yield strength. The stress required for crack propagation is lower than that for crack initiation. As a result, the crack initiation and propagation are seen instantaneously with a complete fracture of the metal. Fracture surfaces are usually completely covered with the liquid metal. The movement of the liquid metal into the crack is attributed to the rapid crack propagation through the material. In some cases, solid metals at temperatures in the vicinity of their melting points have also been shown to cause embrittlement. This phenomenon has been termed solid metal induced embrittlement (SMIE). Table 20 lists LME interactions of various metals.