Spray deposition in a low pressure environment

摘要

Spray atomization of molten metal (30) and/or intermetallic matrix composites reinforced with ceramic particles (46) is practiced by atomizing the matrix into micron sized droplets and depositing the semisolid droplets in a bulk deposition upon a temperature controlled substrate (54). The semisolid droplets are injected with refinement particles (46) while in a range of 0 to 40 % by volume solid phase and deposited on the substrate surface (54) while in a 40 to 90 % by volume solid phase. Refined grain morphology, increased solid solubility, nonequilibrium phases, absence of macro segregation, and elimination of the need to handle fine reactive particles are all achieved by performing the spray deposition process in a vacuum or at least a partial vacuum. Materials fabricated by the process exhibit a significantly lower level of porosity and higher superplasticity than conventionally spray formed deposits.