Processing And Mechanical Characterization Of H2sm-5 Zeolite Loaded With Transition Metals Catalysis For Single Step Conversion Of Mehthane To Gascoline

Abstract

Magnesium-based composite is designed for heavy-duty application especially in automotive (crankcase, gearbox) and aerospace industry (transmission housing). During the servicing period of components, they will experience severe fluctuating stresses or cyclic loading which can lead to unforeseen catastrophic failure. Thus, the understanding of fatigue behaviour is very important in the design and manufacture of such engineering component. However, the literature on the mechanisms of deformation especially fatigue strength of magnesium based composite is poorly understood and it is difficult to get a clear picture of the subject. Therefore, this research aims at a comprehensive understanding of the processing and mechanical characterisation of magnesium MMCs, which is produced through compocasting technique. Influence of microstructural parameters is extensively studied, i.e. weight fractions and average size of reinforcement particles. The specimens are tested under constant amplitude cyclic loading in the range of 2 kN- 4 kN with the load ratio of 0.1 at room temperature. The fatigue performance would be thereafter analysed through microstructural observation on the fractured and as-polished surface. The fatigue result obtained showed that the composite reinforced with 10 wt.% of SiC reinforcement has the best fatigue performance, followed by 15 wt.%, 5 wt.% and lastly unreinforced matrix alloy. From the fractographic observation, it is apparent that fatigue fracture is matrix phase dominated. The crack will initiate at the regions with casting defects or higher concentration of SiC reinforcements. Subsequent propagation can also be noticed within the ductile matrix phase, by avoiding the hard and brittle reinforcement. Microscopic examination revealed that interface debonding or particle cracking is rarely observed