Analysis of wear resistance of Fe-Al graded materials

Tomasz Durejko, Stanisław Lipiński

Quarterly No. 3, 2010 pages 195-199

DOI:

keywords: powder metallurgy, Fe-Al intermetallic phases, Fe-Al graded materials, „pin on disc”

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abstract The analysis of wear resistance of Fe-Al graded materials was presented in this paper. The materials were produced by the laminar batch preparation of the matrix, by the use of the numerically controlled batch head. Cold compressed compacts were sintered under the periodically changing load, and then were annealing at the temperature of 1200°C in the inert gas atmosphere. Two technological variants of Fe-Al graded materials were manufactured: continuous and discrete (three samples for every variant). Wear abrasion test was performed in air temperature on a pin-on-disc T10 apparatus. The samples were prepared by electric discharge machining. The dimensions of the Fe-Al gradient pin were 3.5 mm in diameter by 4.2 mm in height. The pin was pushed against counter face (0H18N9 alloy, average hardness 30 HRC) with a pressure of 1.6 MPa at sliding velocity of 0.2 m/s during 2 hours. Every gradient samples wearing off from two sides: “pure iron” and Fe50Al phase. The results of wear test was presented as loss linear dimension and change of friction coefficient versus time of sliding. Additionally, the surfaces of the each frictional couple (pin and face counter) were examined by profilometer (analysis of roughness profiles - Ra and Rz parameters) and observed by SEM using BSE method. It was found the friction coefficient was comparable for all investigated friction couples, and its value was about 0.5. Additionally, wear level of continuous and discrete Fe-Al gradient was the same both pure iron side and Fe50Al side. Therefore further investigation carried out only one technological variant. It was stated the loss linear dimension for Fe-0H18N9 couple is about 600 μm versus of 30 m wear of Fe50Al-0H18N9. Analysis of the surfaces of “pure Fe” and Fe50Al side and after dry-friction wearing, indicates that dominant mechanism of wearing is adhesive. The wearing of counter sample (0H18N9 steel) is quite different. Analysis of wear traces micrographs for indicates wear of counter face is a combination of adhesive wear, abrasion and erosion. The mechanism of wearing is near abrasive for counter face mated with Fe50Al side of Fe-Al gradient.