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Wan Abdul Rahman Assyahid Wan Ibrahim
Preferred name
Wan Abdul Rahman Assyahid Wan Ibrahim
Official Name
Wan Abdul Rahman Assyahid, Wan Ibrahim
Alternative Name
Wan Abdul Rahman Assyahid, Wan Ibrahim
Wan Abd. Rahman Assyahid, Wan Ibrahim
Main Affiliation
Scopus Author ID
56943590200
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PublicationOptimization of heating rate on hybrid microwave sintering of the PM Fe-Cr MMCs reinforced with Al2O3particleThis study reports the optimization of heating rate on the microwave sintered Fe-Cr-Al2O3 metal matrix composite (MMC). The heating rate was selected between 10°C/min to 60°C/min with increment of 10°C/min respectively. The samples were fabricated via PM route and microwave sintering was carried out in a tubular microwave furnace HAMiLab-V3 in N2 atmosphere purposely to avoid any oxidation and chemical reaction to samples. The microstructure of sintered samples was evaluated using SEM and bulk density and porosity were determined based on ASTM B962 - 17 and the microhardness were determined based on ASTM E384. The optimized heating rate of the sample was selected based on the micro hardness value and total porosity percentage as well as based on SEM microstructure analysis. The results revealed that the optimum heating rate occurred at 20°C/min due to the highest value of hardness achieved which is about 119.28 HV with at the highest bulk density about 6.07 g/cm3 and at the lowest total porosity about 14.55%. SEM micrographs also showed that the diffusion was mostly effective at 20°C/min heating rate compared to others, indicated that significant grain boundary diffusion of Fe matrix into Al2O3 particle was occurred.
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PublicationThe effects of alumina on the hybrid microwave sintered ferum-chromium metal matrix compositesThe main problem with conventional sintering is because of the lower heating rate leads to longer processing time, resulted in higher energy consumption. To overcome the problems, sintering with microwave energy has been introduced. However, this research is still new and limited to some pure metals, pure ceramics and a few types of composite materials only. This study involves fabrication of ferum-chromium (Fe-Cr) matrix reinforced by alumina (Al2O3) particles sintered under hybrid microwave energy at four (4) different sintering parameters such as compaction pressure, heating rate, sintering temperature and holding time. The study were focused on determination of the optimum mechanical properties such as bulk density), total porosity and micro hardness and mechanical wear characteristics in-term of volume lost (mm3), wear rate (mm3/s) and wear coefficient (K) by varying the Al2O3 particles content from 5 wt.% to 30 wt.% of fe. Hybrid microwave sintering was performed using microwave furnace Hamilab-V3 at 2.45 GHz at output power of 3kW. This study found the optimum condition for compression pressure, heating rate, sintering temperature and holding time occurred at 700 MPa, 20°C/min, 1400°C and 45 minutes. Total sintering time under hybrid microwave energy at this setting was 130 minutes compare to 340 minutes achieved by conventional sintering. This means hybrid microwave sintering was 62% faster than conventional sintering. Incorporating of 30 wt.% Al2O3 particles to Fe-Cr matrix deteriorated the bulk density from 6.652 g/cm3 to minimum at 4.08 g/cm3 and concurrently, increase in total porosity percentage from 11.24% to 22.60%, microhardness achieved at highest value at 170HV. This study revealed that mild wear occurred for sample with low Al2O3 particles at 5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%. Severe wear mostly by abrasive wear significantly occurred for samples with 25 wt.% and 30 wt.% of Al2O3 content. The wear resistant coefficient (K) was found at highest value 1.2 x 10-1 for the Fe-Cr composite reinforced with 30 wt.% of Al2O3 particles. The high wear rate that contributed aggravated wear resistant occurs at 25 wt.% and 30 wt.%, while the low wear rate that provide highest wear resistant was achieved when between 5 wt.% to 20 wt.% of Al2O3 particles is added to Fe-Cr matrix.
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