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In this research, the metallic phase Aluminium (Al) and the ceramic phase Aluminium Oxide (Al2O3) were combined in different proportions for the preparation of five-layered Al-Al2O3 functionally graded material. Delamination or crack is the common problem at the metal-ceramic interface because of the large difference in material properties. Therefore, the main objective of this research was to investigate the defects within the layer during processing of the graded structure. The compositions of different weight percentages of five-layered structure are 100%Al+0%Al2O3, 95%Al+5%Al2O3, 90%Al+10%Al2O3, 85%Al+15%Al2O3 and 80%Al+20%Al2O3. During preparation of the graded composite structure, conventional two-step sintering cycle was followed. Heating rate 2°C/min, sintering temperature 630°C and sintering time 3 hours were maintained. It was observed that there was uniform distribution of Al2O3 ceramic particle in the Al matrix with the minimum of agglomeration, all interfaces were almost parallel with layers boundary and gradual transition occurred from first layer to fifth layer which confirmed the proper preparation processes of the five-layered graded composite structure. In addition, it was evident that there was no existence of crack within any layer or interface of the prepared composite structure.

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Functionally graded material that consists of gradually changed dual-phase compositions along the thickness direction of its structure has been introduced as an answer to sharp interfaces problems occur while the processing. In order to observe the morphological and shrinkage due to the sintering process, the Ni/Al2O3 FG samples were manufactured via powder metallurgy routes under argon atmosphere. This study reveals that the sintering temperature does affects the sintering behaviors including the microstructures and radial dimensions of the FG plates. The numerical simulation is found to be useful to predict the stress concentration area within the structures and consequently improve the design of the FG plates.

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