Numerical and experimental study on WEDM of BN-AlN-TiB2 composite ceramics based on a fusion FEM model

Abstract

Due to the poor machining performances in the traditional machining process for BN-AlN-TiB2 composite ceramics, this paper investigated the influence of electrical parameters and material composition on the machining performances of wire electrical discharge machining, namely material removal rate (MRR), surface roughness, kerf width, and energy efficiency. To find out the optimal process parameters, a fusion thermo-physical model based on the finite element method was proposed to predict the machining performances of BN-AlN-TiB2 with different weight proportions. Compared with experimental results, the accuracy of the novel model was verified within a relative error of 24.56, 16.16, and 1.87% in MRR, surface roughness, and kerf width, respectively. In addition, a series of experiments were conducted to investigate the effects of process parameters on machining performances for WEDM of different BN-AlN-TiB2 composite ceramics with 6, 8, and 10 wt% TiB2. The experimental results demonstrated that machining performances were proportional to the discharge energy. Moreover, MRR and specific discharge energy increased with increase of discharge current and pulse-on time. Considering the machining performances and energy efficiency, an appropriate parameter range with discharge current of 6–8 A, pulse-on time of 10–30 μs, and pulse-on time of 4–6 μs was recommended, and the BN-AlN-TiB2 composite ceramics with 6 wt% TiB2 exhibit better energy efficiency during the WEDM process.