Thermomechanical Fatigue Behavior of Spray-Deposited SiC_p/Al-Si Composite Applied in the High-Speed Railway Brake Disc

Abstract

The thermomechanical fatigue (TMF) behaviors of spray-deposited SiCp-reinforced Al-Si alloy were investigated in terms of the size of Si particles and the Si content. Thermomechanical fatigue experiments were conducted in the temperature range of 150-400°C. The cyclic response behavior indicated that the continuous cyclic softening was exhibited for all materials, and the increase in SiC particles size and Si content aggravated the softening degree, which was attributed to dislocation generation due to differential thermal contraction at the Al matrix/Si phase interface or Al matrix/SiC particle interface. Meanwhile, the TMF life and stress amplitude of SiCp/Al-7Si composites were greater than those of Al-7Si alloy, and increased with the increasing SiC particle size, which was associated with “load sharing” of the direct strengthening mechanism. The stress amplitude of 4.5μmSiCp/Al-Si composite increased as the Si content increased; however, the influence of Si content on the TMF life was not so significant. The TMF failure mechanism revealed that the crack mainly initiated at the agglomeration of small-particulate SiC and the breakage of large-particulate SiC, and the broken primary Si and the exfoliated eutectic Si accelerated the crack propagation.

Impacts of nano-clay particles and heat-treating on out-of-phase thermo-mechanical fatigue characteristics in piston aluminum-silicon alloys

“…7 (h) a rapid cyclic softening occurred for AlSi_N_HT6 during the first 20 cycles and the rate of cyclic softening decreased during the TMF cycles until the final fracture. Such a similar behavior was observed for the reinforced AlSi alloy under TMF testing in literature [51]. However, no considerable variations were seen for the stress amplitude of AlSi during fatigue lifetime.…”

“…Higher stress amplitude and lower plastic strain for the heat-treated nano-composites illustrate that the heat treatment made the material behave in a brittle manner, as also reported by Azadi [14]. Higher stress levels for the reinforced specimens were also reported in literature [51] which was due to increasing the Si content in the material composition. Compared to TMF testing at the maximum temperature of 250 °C and 300 °C, the TMF lifetime of both reinforced and unreinforced specimens decreased as the maximum temperature increased to 350 °C.…”

“…This phenomenon is due to the formation of specific intermetallics or eutectic phases such as Si with magnesium, iron, or copper in the microstructure [50]. Moreover, increasing the Si content in the material which was about 51% of a compound constituent of nano-clay particles could increase the rate of cyclic softening [27,51]. Higher values of stress amplitude and lower values of plastic strain for the reinforced specimen showed that reinforcement imposed a brittle behavior on the material.…”

Numerical and experimental study of the relationship between friction area and temperature of aluminium-based brake disc

“…With the deepening of research, aluminium-based brake disc has gained attention in recent years. [24][25][26] Its specific heat capacity and thermal conductivity are somewhat different to those of steel. It is biased to apply previous data to predict the aluminium-based brake discs temperature.…”

Densification of SiCp/Al–Fe–V–Si Composites by the Wedge Rolling Method

“…At present, Al–Si alloy is widely used in electronic packaging, aerospace, and other fields, as per Li et al [ 2 ] and Jia et al [ 3 ]. In particular, alloys reinforced with dispersion precipitation, grain reinforced alloys, or whisker reinforced alloys were found to be more attractive [ 4 , 5 , 6 , 7 ].…”