| The convention spraying is carried on in the atmosphere, and metal particles heated to a high temperature in air is very easily to be oxidized, therefore, there exist a considerable amount of oxides in composite sprayed in air. Through control the spraying atmosphere, the oxidation can be reduced on particle surface. Composite sprayed in controlled atmosphere is more compact, less oxidated and higher bond strength,so can be used to produce special capability material.The 4Cr13,FeCrAl,Al and Ti substrate material sprayed in air and controlled atmosphere are compared, and it is showed that there are many oxidation coating between the grain of microstructure sprayed in air, thus, grain diffusion and continuity of metallurgical reaction are destroyed, and prevent the particle from growing through grain boundary to achieve the metallurgical bond. This is the most significant factor to reduce the bond strength. Microstructure sprayed in controlled atmosphere(Ar) is hardly oxidated, and hardly be found the samdwich, but, there exist a number of pore. Parts between grains which there are no pore have grown to co-grain. Metallurgical bond has taken place.Load 1.5σ_s on 4Cr13,FeCrAl,Al and Ti sprayed in controlled atmosphere and Al sprayed in air, thus reduce the pore for a certain extent, and provide power for recrystallization.The workpiece pressed working and the workpiece not pressed working have been both vacuum heat treated. Through observing the change of organization and morphology, it was found that the cold-worked workpiece under vacuum heat treatment has recrystallized and the organization has changed, thus generating more co-crystal grain.
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