Study On The Technology Of Electrical Discharge Machining Al-SiC_p Composites

Aluminum matrix composites are a kind of special material, which is mixed a certain degree of reinforcement with aluminum and treated by a series of processes. The performance of aluminum matrix composites depends on the characteristics, content and distribution of matrix alloy and reinforcement. Aluminum matrix composites have good physical and chemical properties compared with the base alloy. It is used in the automotive, aerospace and many other fields as a new material. It has great significance to study the processing technology and mechanism for promoting the application of this material.The regularity of processing efficiency and surface roughness are influenced by the electrical parameters, such as pulse on time, pulse off time, the peak current and servo voltage and so on. Wire Electrical Discharge Machining(WEDM) is studied in this paper. The SiC particle content has two kinds of 5% and 10%. The copper and graphite electrodes were used in the EDM to study the regularity of machining efficiency which is influenced by the electrode, and EDM electrical parameters were optimized. Surface morphology and structure were measured by SEM and X-ray energy spectrum. Machining mechanics of Electrical Discharge Machining Al-SiCp composites was discussed.The results showed that the processing efficiency increases to the peak with the pulse on time first and then decreases, and it decreases with the increases of pulse off time and servo voltage, in addition, it also increases with the increases of peak current in the progress of WEDM. Surface roughness was increased with the pulse on time and peak current, which was decreased with the increase of pulse off time and servo voltage. Different optimized electrical parameters were dependent on the maching of different content of SiC particles. The results of EDM showed that the optimal processing parameters were the pulse on time (17μs), pulse off time (55-95μs), the peak current (50A) and servo voltage (75V) when graphite electrodes were machined. on the other side, the optimal processing parameters were pulse on time (19- 21μs), pulse off time (65μs), the peak current (65A), servo voltage (75V) as the copper electrode were machined.