Application of aluminide coatings modified with yttrium for protecting corn post-harvest processing equipments against erosion in food industries

Recent studies demonstrate that aluminide coatings are beneficial to wear and erosion resistance and also oxygenactive elements such as yttrium can remarkably improve this resistance. In this research, the micro-hardness of the aluminide coatings with and without yttrium on carbon steel AISI 1045 was investigated using a micro-mechanical probe in post-harvest processing equipments in food industries. Wear of the samples was measured using a pin-on-disk tribometer. The erosion loss of specimens against five varieties of corn was also evaluated using a slurry erosion test machine. Experimental data were analyzed statistically using a 5-factor completely randomized design to study the effect of corn varieties, moisture content at three levels (13, 15, and 17% (wet basis)), and rotation velocity of the slurry erosion machine at three levels (150, 300, and 450 rpm) on erosion resistance. The results showed that the aluminide coatings improved the wear and erosion resistance of substrate carbon steel AISI 1045; yttrium markedly improved the hardness of the aluminide coating and its wear and erosion resistance. The erosion loss of materials was significantly (P < 0.01) influenced by the variety of corn, moisture content and rotation velocity. Both aluminide coating without yttrium and aluminide coating with yttrium showed higher wear and erosion resistance than carbon steel AISI 1045 substrate.