MICROSTRUCTURE AND PROPERTIES OF HIGH Si ALLOY ZA27 PRODUCED BY SPRAY DEPOSITION

The microstructure and high-temperature properties of ZA27 alloy containing 4% Si and 0.3 % Fe produced by spray deposition are investigated. The microstructure of the alloy was made up of porosity(2% 4%), spheroial and uniform silicon-riched phases(30% 40%) and three kinds of substrate. The micro-hardness(HV) and high-temperature hardness(HB) of the alloy produced by spray deposition or conventional casting process make no difference before aging, but all the above properties is greatly improved by spray deposition after aging.