Annual Technical Report.

Abstract : Progress is reviewed for a research program which has examined the multiaxial deformation and fracture behavior of Ti alloys, particulary as influenced by impurities such as hydrogen and by microstructural defects such as porosity. The studies range from experimental and analytical modeling of critical fracture processes to structure-property studies of both wrought material in the form of sheet and powder fabricated material in bar form. Specifically the program has studied: (1) the modeling of ductile fracture through an examination of the deformation and fracture at isolated holes in plane-strain tension; (2) the deformation and fracture of P/M Ti and Ti-6A1-4V containing porosity; (3) the influence of hydrogen on the multiaxial deformation and fracture behavior of beta-phase (bcc) Ti-30V and alpha (hcp)-beta Ti-6A1-4V; and (4) the theory of localized necking of sheet at negative minor strains.