ABSTRACT

The utilization of Ti-6Al-4 V for several engineering applications is usually not viable, due to the high cost associated with its machining. The poor thermal conductivity and high strain rate of Ti-6Al-4 V results in high concentration of stress at the cutting tool edge, leading to rapid tool degradation and subsequently poor surface integrity. This significantly affects the overall machining cost. Notwithstanding, the high hardness and toughness of WC-Co cemented carbide tools give them some leverage in Ti-6Al-4 V machining, but concerns over unstable prices, scarcity, toxicity and rapid degradation of cobalt have led investigations into alternate binder metals. This study investigates the effect of nickel as an alternate WC binder, pulsed electric current sintering (PECS) and minimum quantity lubrication (MQL) on mechanical properties and performance characteristics during face milling of Ti-6Al-4 V. The mechanical properties of the cutting tool inserts assessed were hardness and fracture toughness, while performance characteristics assessed were cutting forces, flank wear of the cutting tool inserts and surface roughness of the machined Ti-6Al-4 V surfaces.

摘要

由于与加工相关的高成本，将 Ti-6Al-4 V 用于多种工程应用通常是不可行的。Ti-6Al-4 V 的导热性差和应变率高，导致切削刀具边缘应力集中，导致刀具快速退化，进而导致表面完整性差。这会显着影响整体加工成本。尽管如此，WC-Co 硬质合金刀具的高硬度和韧性使其在 Ti-6Al-4 V 加工中具有一定的影响力，但对价格不稳定、稀缺性、毒性和钴的快速降解的担忧导致对替代粘合剂金属的研究。本研究调查了镍作为替代 WC 粘合剂的效果，