Micro-machinability of nanoparticle-reinforced Mg-based MMCs: an experimental investigation

Abstract

As a composite material with combination of low weight and high engineering strength, metal matrix composites (MMCs) have been utilised in numerous applications such as aerospace, automobile, and bioengineering. However, MMCs are recognised as difficult-to-cut materials due to their improved strength and high hardness of the reinforcing particles. This paper presents an experimental investigation on micro-machinability of Mg-based MMCs reinforced with Ti and TiB 2 nano-sized particles. The tool wear of AlTiN-coated micro-end mills was investigated. Both abrasive and chip adhesion effect were observed on the main cutting edges, whilst the reinforcement materials and volume fraction play an important role in determining the wear type and severity. The influence of cutting parameters on the surface morphology and cutting force was studied. According to analysis of variance (ANOVA), depth of cut and spindle speed have significant effect on the surface roughness. The specific cutting energy, surface morphology and the minimum chip thickness was obtained and characterised with the aim of examining the size effect. Furthermore, higher cutting force and worse machined surface quality were obtained at the small feed per tooth ranging from 0.15 to 0.5 μm/tooth indicating a strong size effect. Overall, Mg/TiB 2 MMCs exhibit better machinability.

Finite element modelling on cutting mechanism of nano Mg/SiC metal matrix composites considering cutting edge radius

“…Based on these results, the minimum chip thickness can be proposed to be 0.5 µm (0.5R) under the input parameters utilised in this FE model. This result is consistent with that obtained from research carried by Teng et al [20], which is 0.53R in micro machining of Mg/TiB2 with volume fraction of 1.98%. Moreover, an increase in the shear angle can be found with the uncut chip thickness (Figure 16).…”

An experimental investigation on surface generation in ultraprecision machining of particle reinforced metal matrix composites

“…As a result, particles are cut through with few defects at higher cutting speed. However, the higher cutting speed results in the increase of cutting temperature, which will lead to rapid tool wear and reduce the machined surface quality [15]. Thus, a better surface performance can be obtained when increasing the cutting speed properly.…”

Hybrid Reinforced Magnesium Matrix Composites (Mg/Sic/GNPs): Drilling Investigation

“…A high feed rate causes comprehensive surface damage due to a high contact pressure, and fine grooves and cracks are observed, caused by the strain hardening of the Mg matrix material [18]. Figure 13 shows the SEM image of the drilled surface at Vc = 50 m/min and f = 0.10 mm/rev while using the uncoated drill bit.…”