Abstract:
This research studied the effect of humidity and environment to the flowability and compactability of metal powders. Iron, copper and graphite powders were selected to test adhesion force between particles by centrifuge technique, The flowability was tested by flow meter and angle of repose. The compactability was tested by compaction powder, partical singering, microstructure of pore and hardness. All methods were studied from 20 to 98 percent relative humidity (HR), which were controlled by salt solution and silica gel. Adhesion forces between particles were affected from liquid bridge (Capillary force) by humidity in air. Capillary force decreased flowability and compactability at high relative humidity. The possibility of humidity adsorption in metal powders was studied by using Rice Husk Ash (RHA). This product was burned from rice husk, which high silica content 99.693 % could be produced after 3-mol HCI treatment and heat-treating at 700 degree Celsius by heating rate 5 degree Celsius/min. SEM, SRD, XRF, TGA, Laser Particle Size Analyzer, BET method, were used to investigate the properties of reactant and product including morphology, thermal decomposition, particle size distribution, and surface area. The specific surface area of silica ash was 294.53m /g, the average particle size was 5 m. All products were amorphous silica. The result show that the silica ash could be absorbed humidity, which increased flowability and compactability in metal powders.