DENSIFICATION STUDY OF TITANIUM POWDER COMPACTS Márcia Cristina Carneiro Ueta (1) , Carlos Augusto Fracote (1) , Vinicius André Rodrigues Henriques (2) , Mario Lima Alencastro Graça (2) , Carlos Alberto Alves Cairo (2) (1)Universidade do Vale do Paraíba – UNIVAP (2) Centro Técnico Aeroespacial, AMR/IAE/CTA Key-words: Powder Metallurgy, titanium powders, Hydride-Dehydride Process (HDH), densification. Abstract: Powder compaction characteristics is a very important parameter to control in order to obtain products with best mechanical properties made by P/M techniques. This work presents a study on the densification of titanium powders trying to optimize the particle size distribution for the best packing and the maximum densification by pressure compaction. The powders used were made from titanium sponge obtained by the Kroll process. The powders were embrittled by mean of the Hydride-Dehydride process (HDH) and milled in a rotative ball-mill under vacuum. Powders with different particles sizes distributions were mixed in several proportions according to Alfred's and Andreasen’s Theory. The samples were compacted by uniaxial and isostatic pressing and sintered under vacuum. The evaluation of the densification was made following the Standard method of test for density of glass by Buoyancy (ASTM – C693-74) and by scanning electron microscopy (SEM). The samples made with powder milled during 36 hours and 12 hours presented better densification than the ones milled during shorter time and the ones with distributions combinations. Introduction Traditional metallurgic processes to obtain titanium alloys are very expensive, due to the high reactivity of the titanium. Powder metallurgy technology enables to produce high quality metallic components with complex parts and low tolerances (near net shape), with lower costs. However, the disadvantage of this process is that the metallic components present high porosity after sintering, and consequently lower mechanic strength when compared with other producing methods. The utilization of powder with optimized size particle distribution which allow better packing during the pressing before sintering is a way to solve this problem. The principle of particle packing is based on selecting particles in such sizes and fractions that produces compacts with controlled density [1]. Particle size distribution that enable to obtain dense compacts shows some advantages like minimizing dimensional changes during drying or firing and improving the compound’s properties. Alloys without macropores and with higher mechanic strength is also favored by using this optimized particle distribution [2]. Dense packing of particles is based on selecting particles in such sizes and fractions that voids between larger particles are occupied by successively smaller particles. The remaining porosity is then composed of interstices created by the non-existence of smallest particles in the 08/ 04