Wear mechanisms in hybrid composites of graphite-20 pct SiC in A356 aluminum alloy (Al-7 pct Si-0. 3 pct Mg)

Journal Article · Sun Jan 01 00:00:00 EST 1995 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02669796· OSTI ID:6607413

Ames, W; Alpas, A T ^[1]

---

1. Univ. of Windsor, Ontario (Canada). Dept. of Mechanical Engineering

The wear behavior of A356 aluminum alloy (Al-7 pct Si-0.3 pct Mg) matrix composites reinforced with 20 vol pct SiC particles and 3 or 10 vol pct graphite was investigated. These hybrid composites represent the merging of two philosophies in tribological material design: soft-particle lubrication by graphite and hard-particle reinforcement by carbide particles. The wear tests were performed using a block-on-ring (SAE 52100 steel) wear machine under dry sliding conditions within a load range of 1 to 441 N. The microstructural and compositional changes that took place during wear were characterized using scanning electron microscopy (SEM), Auger electron spectroscopy (AES), energy-dispersive X-ray spectroscopy (EDXA), and X0ray diffractometry (XRD). The wear resistance of 3 pct graphite-20 pct SiC-A356 hybrid composite was comparable to 20 pct SiC-A356 without graphite at low and medium loads. At loads below 20 N, both hybrid and 20 pct SiC-A356 composites without graphite demonstrated wear rates up to 10 times lower than the unreinforced A356 alloy due to the load-carrying capacity of SiC particles. The wear resistance of 3 pct graphite 20 pct SiC-A356 was 1 to 2 times higher than 10 pct graphite-containing hybrid composites at high loads. However, graphite addition reduced the counterface wear. The unreinforced A356 and 20 pct SiC-A356 showed a transition from mild to severe wear at 95 N and 225 N, respectively. Hybrid composites with 3 pct and 10 pct graphite did not show such a transition over the entire load range, indicating that graphite improved the seizure resistance of the composites.

• OSTI ID: 6607413
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 26:1; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
WEAR
COMPOSITE MATERIALS
GRAPHITE
SILICON CARBIDES
CHEMICAL COMPOSITION
EXPERIMENTAL DATA
MECHANICAL TESTS
MICROSTRUCTURE
TRIBOLOGY
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON
CARBON COMPOUNDS
DATA
ELEMENTAL MINERALS
ELEMENTS
INFORMATION
MATERIALS
MATERIALS TESTING
MINERALS
NONMETALS
NUMERICAL DATA
SILICON COMPOUNDS
TESTING
360603* - Materials- Properties