THE reduction in ductility and fracture stress of many metals tested in certain liquid metal envi-ronments is generally known as liquid metal embrittlement(LME).The resistance to fractureR=(1-v~2)K_(IC)~2(L)/E,calculated by the fracture toughness K_(IC)(L)in LME,is often 1—3orders of magnitude greater than the surface energy of the material,γ.Orowan’s equationof R=2γ_(eff)=γ+γ_P must be used in considering LME rather than Griffith’s equation of R=2γ,where γ_P is plastic work done.The experiments in LME showed that γ_P=(10—1 000)γ.It has been shown that there is localized plastic deformation in brittle failure induced bythe chemisorption of liquid metal. The reduction in ductility and fracture stress of many metals tested in certain liquid metal envi-ronments is generally known as liquid metal embrittlement (LME). The resistance to fracture R = (1-v ~ 2) K_ (IC) ~ 2 (L) / E, calculated by the fracture toughness K_ (IC) (L) in LME, is often 1-3 orders of magnitude greater than the surface energy of the material, γ.Orowan’s equation of R = 2γ - (eff) = γ + γ_P must be used in considering LME rather than Griffith’s equation of R = 2γ, where γ_P is plastic work done. The experiments in LME showed that γ_P = (10-1 000) γ. It has been shown that there is localized plastic deformation in brittle failure induced by the chemisorption of liquid metal.