Abstract:
The composites of Iron aluminide (FeAl) matrix reinforced with Alumina (A12O3) have been prepared by two step method. Pure elemental powders of Fe and Al were used to make Iron aluminide of composition Fe-40 at% Al by mechanical alloying in the first step. Planetary ball mill (Retsch PM200) was used with tungsten carbide (WC) balls as grinding medium, Ball to Powder Ratio (BPR) 10:1 and speed of rotation of disk 375 rpm as processing parameters. The intermetallic was formed after 24 hours of milling, confirmed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). In the second step, homogeneous dispersion of A12O3 as reinforcement in FeAl was done by mechanical milling. Four composites with 10, 20, 30 and 40 vol% A12O3 were obtained and then each composite was uniaxially diepressed under pressure range of 499-1247 MPa. Increase in green density was observed with increase in A12O3 content. Sintering of most dense composite pellets was done at 900°C for 90 minutes in argon atmosphere. Maximum density achieved after sintering was 93% of theoretical density, with 40 vol% A12O3. The Knoop hardness was found to increase with A12O3 content. Variation of hardness from point to point was not much, which indicates that A12O3 is homogeneously distributed.
Page(s):
37-44
DOI:
DOI not available
Published:
Journal: Proceedings 6th International Bhurban Conference on Applied Sciences and Technology , Volume: 1, Issue: 0, Year: 2009