JOINING DISPERSION-STRENGTHENED, RAPIDLY SOLIDIFIED, P M AL-ALLOYS/

The weldability of dispersion-strengthened, rapidly solidified Al-Fe a lloys is limited by the residual hydrogen content, solidification beha vior, and the high-temperature deformation behavior of these alloys. C onsequently, the selection and application of welding processes and co nditions to join these aluminum alloys-either to themselves or with ot her engineering alloys-must be based on the ability of the welding pro cess conditions to eliminate or minimize the occurrence of fusion zone porosity; ''recreate'' a microstructure similar to the rapidly solidi fied, powder metallurgy base alloy; and/or ''retain'' the superior bas e alloy microstructure in the weld zone. Toward this end, an understan ding of the physical metallurgy and high-temperature deformation chara cteristics of the dispersion-strengthened, rapidly solidified, powder metallurgy Al-Fe alloys and the effects of welding process conditions and parameters on weld solidification behavior and microstructural dev elopment in the weld zone will enable one to optimize welding conditio ns to obtain desirable combinations of weld microstructure and mechani cal properties.