Machining of metal matrix composites: Effect of ceramic particles on residual stress, surface roughness and chip formation

Abstract

a b s t r a c tMachining forces, chip formation, surface integrity and shear and friction angles are important factors to understand the machinability of metal matrix composites (MMCs). However, because of the complexity of the reinforcement mechanisms of the ceramic particles, a fair assessment of the machinability of MMCs is still a difficult issue. This paper investigates experimentally the effects of reinforcement particles on the machining of MMCs. The major findings are: (1) the surface residual stresses on the machined MMC are compressive; (2) the surface roughness is controlled by feed;(3) particle pull-out influences the roughness when feed is low; (4) particles facilitate chip breaking and affect the generation of residual stresses; and (5) the shear and friction angles depend significantly on feed but are almost independent of speed. These results reveal the roles of the reinforcement particles on the machinability of MMCs and provide a useful guide for a better control of their machining processes.

Influence of graphite particles on surface roughness and chip formation studies in turning metal matrix composites

“…Although these composites have excellent performance characteristics, their poor machining efficiency leads to severe cutting tool wear, and difficulty in obtaining the fine surface quality was explained in review by Basavarajappa et al 1 . Pramanik et al 2 , Basavarajappa 3 and Chou and Liu 4 were reported that the main concern when machining of particulate metal matrix composites is extremely high tool wear and poor surface finish due to the abrasive action of the ceramic reinforcing particles compared to monolithic alloys. This is due to the presence of hard ceramic particles in composites, which acts as small cutting edges resulting in poor surface finish.…”

“…It is observed earlier that the deformation during machining of Al/SiCp composites was mainly due to the rupture rather than shear. The chips formed during machining show an asymmetrical waviness, with the chip segments joined to each other by a thin and highly strained region was reported 2,19 . It is also known from the theory of metal cutting that the study of chip formation is the most effective and cheapest way of understanding machining characteristics of the work material.…”

A Study on Cutting Force of Machining In Situ TiB2 Particle-Reinforced 7050Al Alloy Matrix Composites

“…Then the analytical force model can be expressed as follows: In most cases during low speed cutting, cutting speed does not influence the cutting forces significantly. However, according to studies and discoveries of machining ex situ SiC/Al composites [28,29], some contradictory reports were found. With the presence of the BUE (built-up edge), forces at low cutting speeds are lower than that at high speeds.…”

Milling of Nanoparticles Reinforced Al-Based Metal Matrix Composites

“…The complex deformation mechanism due to the presence of reinforcements [19,20] in metal matrix composites (MMCs) causes high tool wear during traditional machining. Numerous reports can be found in literature describing experimental, analytical and numerical investigations related to machining of micro-particle reinforced MMCs.…”