The quality and performance of products produced by the electrical discharge machining process mainly affected by the integrity of the machined surface. The recent development in the various assisted EDM process used magnetic field and mixed-phase dielectric fluids need to examine their effect on surface integrity. Therefore, in the present study, an investigation has been performed to evaluate the effect of a magnetic field and different dielectric conditions mainly liquid, liquid–air and liquid–argon gas mixture on surface integrity in the machining of AISI 304 steel. Their effect on surface and sub-surface features such as surface roughness, micro-cracks, recast layer thickness, heat affected zone, chemical and phase transformation have been compared. In addition, the effect of variation in the pressure of air/argon gas in the mixed phased dielectric and magnetic flux density on surface integrity have also been evaluated. The reactive nature of oxygen from air and inertness of argon gas mixed in liquid dielectric governed the heat supply and heat transfer rate into the discharge crater. The results showed that the assistance of air and argon gas narrow down the surface cracks by 55% and 72%, respectively, as compare to liquid dielectric. The magnetic field reduced the surface roughness by 18% and 32% in the air-assisted EDM and argon gas-assisted EDM, respectively. However, the combined assistance of magnetic field and air/gas increased the thickness of recast layer and HAZ as compared to EDM using liquid dielectric and without assistance of magnetic field.

放电加工过程产生的产品的质量和性能主要受加工表面的完整性影响。使用磁场和混合相介电液的各种辅助EDM工艺的最新发展需要检查其对表面完整性的影响。因此，在本研究中，进行了一项研究，以评估AISI 304钢加工过程中磁场和不同介电条件（主要是液体，液体-空气和液体-氩气混合物）对表面完整性的影响。比较了它们对表面和亚表面特征的影响，例如表面粗糙度，微裂纹，重铸层厚度，热影响区，化学和相变。此外，还评估了混合相介电质中的空气/氩气压力变化和磁通密度对表面完整性的影响。空气中氧气的反应性和混合在液体电介质中的氩气的惰性决定了热量的供应和向放电坑的传热速率。结果表明，与液态电介质相比，空气和氩气的辅助作用使表面裂纹分别缩小了55％和72％。磁场在空气辅助电火花加工和氩气辅助电火花加工中分别使表面粗糙度降低了18％和32％。但是，与使用液体电介质且没有磁场辅助的EDM相比，磁场和空气/气体的辅助作用增加了重铸层和HAZ的厚度。