SUS304L fine powder was made by the newly developed high pressure water atomization equipment.
Our study was made about the influence of atomizing conditions on its powder characteristics, and about the effect of the amount of fine powder added to the conventional -100mesh powder on the mechanical properties of sintered compacts made of these powders.
Results were summarized as follows.
(1) SUS304L fine powder, whose mean particle diameter was under 10μm was made by high pressure water atomization. The equation written below was statistically induced from the result of this work and other data made under the condition of conventional atomizing pressures.
D=794P-0.56Q-0.22L0.15q0.15
D(μm): mean particle diameter
P(kg/cm2): atomizing pressure
Q(l/min): flow rate of atomizing water
L(cm): distance between water outlet of the atomizing nozzle and atomizing point
q(l/min): flow rate of molten metal
(2) The mean particle diameter of fine powders measured on laser diffraction theory was smaller than that on stokes sedimentation theory. It is supposed that the agglomeration of fine powders during sedimentation caused the bigger particle diameter in the latter case.
(3) The addition of fine powder to the conventional -100mesh powder caused a little less compactability, while it had almost no influence on the compressibility. It also gave a big linear shrinkage with the increasing density of sintered compacts. In proportion to this promotion of sinterability, mechanical properties, especially tensile strength of sintered compacts was greatly improved.