A Review on the Use of Nano-powders During Electric Discharge Machining of Titanium Alloys
摘要
Difficult-to-cut materials like titanium and its alloys exhibit superior properties like high resistance to corrosion, excellent strength-to-weight ratio, and more stability at elevated temperature. Due to this, these are widely preferred in aerospace, biomedical, and automotive industries for components like turbine blades, implants, and high-performance engine parts. Machining of such materials become challenging due to its low elastic modulus, hardness, and poor thermal conductivity. The traditional machining methods impose lot of challenges. Thus, electrical discharge machining (EDM), a type of non-traditional processes, was found to be more appropriate in processing of such materials. The challenges faced by the EDM process are lower cutting rate, larger tool wear, reduced surface quality, and recast layer thickness. To eliminate those challenges, the highly electrically and thermally conductive nano-powders need to be added to the dielectric fluid of EDM. These nano-particles in the dielectric gives the improved machining performance and surface morphology. The powders such as alumina (Al2O3), aluminum (Al), multiwall carbon nanotubes (MWCNTs), nano-graphene, expanded graphite, silicon (Si), and silicon carbide (SiC) are used as a powder additive. The addition of these nano-powder results in the reduction in breakdown strength of the dielectric fluid which in turn improves the ignition mechanism. Thus, the present paper discusses a brief overview of the use of different nano-powders during the EDM of titanium alloys.