材料期刊网

The thermal behavior of Fe-based powders with different sizes during the plasma transferred-arc powder surfacing process are described theoretically and verified experimentally. The results reveal that when the surfacing current I = 100 A, only particles smaller than 0.06 mm can be melted in the central plasma, and when I = 200 A most of the particles analyzed will be fully melted; particles smaller than 0.075 mm will further be fully evaporated in the plasma central field. It is also revealed that only particles coarser than 0.15 mm retain their original solid states in the 200 A plasma space. It is concluded that Fe-based powders of less than 0.075 mm in size should be re-fused when the surfacing current is in the range of 100-200 A in order to ensure the deposited coating's high performance and to minimize the evaporation loss of the surfacing material. (C) 1998 Elsevier Science S.A.