Abstract:Two thixoforming technologies of 6066 aluminum alloy (Al-1.37Si-1.37Mg-0.77Cu-0.07Mn) produced by multi-layer spray deposition process were studied. The spray-formed materials are of equiaxed and very fine grain (10～20μm). And the grain size coarsens slower than that of conventional casting materials at temperature below the liquidus, which may relate to high temperature particles distributed along the grain boundaries. Extrusion and hot pressing were used as the thixoforming processes respectively. After extrusion the materials show a microstructure of mean grain size below 20μm without obvious recrystallization. The mechanical properties achieved via extrusion and pressing in semi-solid  state attain that of common wrought materials with shorter peak aging time of 4～5 h, about half of that in conventional condition.

Key words: thixoforming; multi-layer spray deposition; 6066 aluminum alloy