Review on ballistic tribology

In this paper, it was investigated that studies about the dynamic failure of reinforced metal matrix composites and fiber composites under high velocity impact was observed. Some of this works on this topic is experimental, and they used normal projectile or Armour piercing projectile in ballistic tests. The other works in ballistic system are computer simulations. They use finite element based program for numerical investigation. According to the studies, high velocity of projectile led to the melting of some surface layers because of the excess heat resulting from high velocity friction. However different failure mechanisms such as radial cracking, melting zones, etc. were earlier determined. In some simulation this results had been supported

Surface characteristics of projectiles after frictional interaction with metal matrix composites under ballistic condition

The surface characteristics of the AK-47 (7.62 mm x 39 mm Armour Piercing) and G3 (7.62 mm x 51 mm Armour Piercing) projectile tips were investigated after impacting an Al alloy reinforced with Al2O3 particles at high velocity. The composite samples were manufactured from Al-7075 by the squeeze casting method and they were subjected to ballistic impact tests as defined in related ballistic standards of the National Institute of Justice standards

Comparison of the surface morphologies of ceramic reinforced metal matrix composite cams after wear tests under dry and wet conditions

The integral engine parts, such as camshaft members, are usually not preferably made of ceramic-reinforced MMC because the margin of compromise on the engine performance is small. However, the lightweight and wear-resistant nature of the mentioned materials can benefit fuel consumption without necessarily compromising engine performance. In this study, Al (AA2124) matrix is reinforced with ceramic particles of two different types (SiC, B4C), size distributions (B4C: 1–7, SiC: 2 and 20 μm), and volume fractions (0, 10, 20, 30 vol.%) to manufacture camshaft cams (lobes). While MMC cams are manufactured by powder metallurgy (300 MPa, 615°C, 30 minutes), spherical graphite cast iron (GGG40) cams are prepared by casting, induction hardening, and machining. The wear behavior of MMC cams is compared with the reference unreinforced AA2124 and conventionally used cast iron cams under dry and virtually created engine-like wet conditions. It was attempted to correlate the percentage increase in the roughness and weight loss with the structure of the cams using SEM, EDX, and macroscopy analysis. Results showed that the initiation of a three-body abrasive wear mechanism for 30 vol.% of the larger SiC particles caused lower wear resistance in the cams under dry conditions. As for the wet conditions, although the cams’ wear resistance increased with increasing ceramic particles’ content, it resulted in enhanced wear in the counterface when larger ceramic particles were used as reinforcement. Overall, higher ceramic content and larger particle size encourage three-body abrasive wear between the interacting surfaces and assist in degraded wear resistance under wet conditions. </jats:p