Spark-plasma sintering (SPS) provides accelerated densification and, in many cases, limited grain growth compared to regular hot pressing and sintering. Possible mechanisms of this enhancement of the consolidation in SPS versus conventional techniques of powder processing are identified. The consolidation enhancing factors are categorized with respect to their thermal and nonthermal nature. This paper analyses the influence of a major factor of thermal nature: high heating rates. The interplay of three mechanisms of material transport during SPS is considered: surface diffusion, grain-boundary diffusion, and power-law creep. It is shown that high heating rates reduce the duration of densification-noncontributing surface diffusion, this favors powder systems’ sinterability and the densification is intensified by grain-boundary diffusion. Modeling indicates that, besides the acceleration of densification, high heating rates diminish grain growth. The impacts of high heating rates are dependent on particle sizes. Besides SPS, the obtained results are applicable to the broad spectrum of powder consolidation techniques which involve high heating rates. The conducted experiments on SPS of an aluminum alloy powder confirm the model predictions of the impact of heating rates and initial grain sizes on the shrinkage rates during the electric current-assisted consolidation. It is noted, that this study considers only one of many possible mechanisms of the consolidation enhancement during SPS, which should stimulate further efforts on the modeling of field-assisted powder processing.

Spark-Plasma Sintering (SPS) involves rapid heating of powder by electric current with simultaneous application of external pressure. Numerous experimental investigations point to the ability of SPS to render highly-dense powder products with the potential of grain size retention. The latter ability is of significance for the consolidation of nano-powder materials where the grain growth is one of the major problems. A model for spark-plasma sintering taking into consideration various mechanisms of material transport is developed. The results of modeling agree satisfactorily with the experimental data in terms of SPS shrinkage kinetics.

Wheel rims are vital components critical to the safety of an automobile. Conventional wheel rims have utilized monolithic materials like aluminium and magnesium alloys in replacement to heavier steel rims. To reduce the weight of the formula car, lightweight composite wheel rims with higher stiffness are explored in the current work. Composite wheel rims are still in their nascent stage for commercial automotive applications, although they are commonly seen more in motorsports. The factors like complex design, high cost, and difficulty in fabrication are some of the demerits of composite wheel rims. Formula Manipal racing has been building race cars for Formula India events for over 13 years, on which aluminium wheel rims were standardly fitted. In the current work, the design and finite element analysis of carbon fibre wheels rims were undertaken to replace the aluminium wheel rims after a thorough consideration of other potential materials also. The modelling was carried out on CATIA3DX®, and finite element analysis was carried out using the ANSYS COMPOSITE PREP/POST (ACP)® module for laminate stackup and structural analysis tools for mechanical response. From the studies, the carbon fibre rims reduced the weight significantly by 42% while improving the factor of safety by 41% as compared to the current aluminium wheel rims while thermally outperforming magnesium and titanium alloys.

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