Microstructure and mechanical behaviour of a SiC particles reinforced Al–5Cu composite under dynamic loading

Abstract

The mechanical behaviour of a composite of Al±5Cu matrix reinforced with 15% SiC particles was studied at different strain rates from 1Â10 À3 to 2.5Â10 3 s À1 using both a conventional universal testing machine (for low strain-rate tests) and a split Hopkinson bar (for tests at dynamic strain rates). Whilst the yield stress of the composite increases as the strain rate increases, the maximum¯ow stresses, 440 MPa for compression and 450 MPa for tension, are independent of strain rate. The microstructures and defect structures of the deformed composite were studied with both scanning electron microscopy and transmission electron microscopy and were correlated to the observed mechanical behaviour. Fracture surface studies of samples after dynamic tensile testing indicates that failure of the composite is controlled by ductile failure of the aluminium matrix by the nucleation, growth and coalescence of voids. # 1999 Elsevier Science S.A. All rights reserved.

Properties of ceramic-reinforced aluminium matrix composites - a review

“…The T6 heat-treated and hot-isostatic-pressed specimens were better with respect to both strength and ductility, as compared to the as-cast specimens. Lu et al (1999) observed a maximum flow stress value of 450 MPa during dynamic tensile tests of SiCp/Al-5% Cu composites at the strain rate of 1 × 10 3 s −1…”

“…Compressive strength, flexural strength and toughness Lu et al (1999), during dynamic compression tests of SiCp/ Al-5% Cu composites, reported that the yield stress increased from 180 to 220 MPa as the strain rates increased from 1 × 10 −3 to 2.5 × 10 3 s −1 (Figure 17). Ravi Kumar and Dwarakadasa (2000), while investigating the effect of matrix strength on the compressive properties of SiC-reinforced Al-Zn-Mg alloy matrix composites, observed that the yield strength increased in both solutionannealed (485°C/90 min) and over-aged (170°C/36 h) conditions, but reduced in the peak-aged (135°C/16 h) condition with the increase in volume percent of reinforcement.…”

Fabrication and heat treatment of ceramic-reinforced aluminium matrix composites - a review

“…For instance, very fine SiC particulate sizes of 1, 2, 3, 3.5 and 5 μm were used by Adeosun et al (2009), Yingfei et al (2010, Schubert andNestler (2011), Song et al (1995), Lu et al (1999) and Jayaram and Biswas (1999), respectively, whereas researchers like Kalkanli and Yilmaz (2008) and Jayaram and Biswas (1999) Step 2. Determination of weight/volume fraction of reinforcement…”

“…Naher et al (2004) designed and built a new quick quench stir caster, fitted with thermocouple and temperature controller arrangement to fabricate MMC ingot. Data logger facilities were incorporated to record Figure 2 An optical micrograph of the as-prepared Al-5% Cu/ SiC (3.5 μm, 15 volume fraction) composite (Lu et al 1999). Figure 3 Size, shape and morphology of SiCp (Kumar and Dwarakadasa 2000).…”

“…They also fabricated in situ titanium diboridereinforced Al-based composite, melting Al-4 wt.% Cu alloy to 850°C and then adding two types of compounds, K 2 TiF 6 and KBF 4 , in an atomic ratio of Ti:2B by stirring. Lu et al (1999) employed powder metallurgy process to produce Al-5% Cu/SiC MMC containing Al-Cu powder of 280 grits and SiC particles with an average particle size of 3.5 μm at a volume fraction of 15%, which were compacted by hot compression under vacuum. The defect-free and uniform distribution of SiC particles in the composite was confirmed by optical micrograph studies, which is shown in Figure 2.…”