Quasicrystalline metal powder: A potential filler for UHMWPE composites

The mechanical and thermal behavior of ultra-high molecular weight polyethylene (UHMWPE)/metallic quasicrystal powder (MQP) composites are evaluated at filler volume fractions (∅ f) of 0.01, 0.02, 0.06 and 0.15. MQP is based on an aluminum alloy, synthesized and characterized to act as a filler for UHMWPE. The preparation of the composites was conducted by compression molding. Morphological analysis reveals larger and smaller MPQ particles, being well distributed, and mechanically anchored in the matrix. The melting temperature was maintained after adding filler, while the crystallinity values decreased. When adding MQP, an improvement in thermal stability is observed by increases in both the initial and maximum weight loss rate temperatures (T_max). However, when the temperature is about 700°C all composites present oxidation due to the MQP presence. The Pukansky model shows that the 0.06 MQP composites have better interfacial adhesion. This is confirmed by the Nicolais-Narkis equation. This contributes to an increase in the modulus of elasticity of the 0.06 MQP composite in respect to the others. The elongation at break was reduced for the 0.15 MQP composite. However, the higher volume fraction of MQP increased the stiffness of the UHMWPE, reflecting its potential for use as a reinforcement. (author)