Surface properties of powder mixed EDM of TaW alloy material

Two kinds of specimens made of a kind of TaW alloy material with high strength and high melting point about 3000°C are processed by a traditional EDM (Electrical Discharge Machining) and a powder mixed EDM separately, and its surface characteristics are tested. After processing, their surfaces have the roughness of 0.542 μm and 0.174 μm, and the modulus of elasticity of 280 GPa and 410 GPa, respectively. Moreover, the surface friction-resistance of the specimens are studied on a CJS111A friction and wear tester. The micro-appearances on the frictionized surfaces are observed and analyzed by using a SEM. The test results indicate that the better friction-resistance ability the specimen has, the higher wear rate the frictionized balls display in the test. The wear rates of frictionized ball corresponding to the two processed surfaces are 2.4 × 10^-5 mm³/m for the traditional EDM and 1.4 × 10^-4 mm³/m for the powder mixed EDM, which shows the latter is 5.8 times of the former. The results show that the powder mixed EDM is better at improving the surface properties of specimen than the traditional EDM, which means that the technique of powder mixed EDM has a great potential in processing the special material.