| Effect of grading pattern on the flexural creep behavior of Al-SiC functionally graded nanocomposites produced by powder metallurgy |
| Paper ID : 1307-UFGNSM-FULL |
| Authors: |
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Farshad Akhlaghi *, Sahar Golmakaniyoon School of Metallurgy and Materials Engineering, Center of Excellence for High Performance Materials, College of Engineering, University of Tehran |
| Abstract: |
| The aim of this study was to investigate the flexural creep behavior of nanoparticle reinforced functionally graded materials (FGMs) and finding the optimum reinforcement concentration grading pattern for achieving the minimum creep rate. In this regard, Al6061 powder particles were mechanically co-milled with different amounts (0.1- 0.5 vol.%) of nano sized SiC powders (25-50 nm) using a high energy ball mill. In order to prepare the nanocomposite powders, a number of milling parameters were modified. Laser particle size analysis was used to evaluate the size and size distribution of powder mixtures during milling and their microhardness was evaluated via a microhardness tester. Also the crystal size and lattice strain of these powders were evaluated by quantitative XRD analysis. The results confirmed that after 28h milling, the SiC nanoparticles were embedded and uniformly distributed within the generated Al nanocrystallites. FGM samples were fabricated through stacking of a fixed number of layers of these nano-composite powders with different graded concentrations in a steel die and hot pressing. In these FGMs, 0.25 vol.% of SiC nano particles were distributed within the thickness of plate shaped samples with three different power law grading patterns having the exponents of 0.67, 1 and 2. Flexural creep behavior of these FGMs at 573 K was investigated. It was concluded that increasing the exponent from 0.67 to 2 resulted in 45% reduction in the creep rate. |
| Keywords: |
| Powder Metallurgy; Functionally Graded Nanocomposites; Stacking Powder Layers; Grading Patterns; Creep. |
| Status : Paper Accepted (Oral Presentation) |
