Papers by Author: Hong Zhang

Abstract: In Micro Wire Electrical Discharge Machining (Micro-WEDM), the kerf width varies with different machining parameters, which will greatly influence the machining precision. In order to study the kerf variations in Micro-WEDM, the influence of kerf variation is analyzed and the experiment considering the kerf width and machining speed are performed on self-developed micro-WEDM under different machining parameters. With the reference of the experiment results, 32μm wide slot is machined with Φ30μm wire-tool on stainless steel workpiece.

Abstract: Two kinds of specimen made of a kind of Ta-W alloy material with high melting point about 3000°C were processed by a traditional EDM (TEDM) and a powder mixed EDM (PMEDM) separately, and its surface characteristics were tested. After processing, their surfaces had the roughness of Ra 0.542μm and Ra 0.174μm, respectively. Moreover, their surface wear-resistance was studied on a CJS111A friction and wear tester. The micro-appearances on the wear surfaces were observed and analyzed by using a SEM. The test results indicated that the better wear-resisting ability the specimen, the higher wear rate displayed during the test the grinding balls. The wear rates of grinding balls corresponding to the two processed surfaces are 2.4×10-5 mm3/m for the TEDM and 1.4×10-4 mm3/m for the PMEDM, and the latter is 5.8 times of the former. The results show that the PMEDM is better at improving the wear-resistance, roughness and hardness than the TEDM, which means that the technique of PMEDM has a great potential in processing the special material.