Improved wear resistance of dendrite composite eutectic Fe-B alloy

The dry-sliding tribological properties of the dendrite composite eutectic Fe-B alloys (Fe_94.3B_5.7, Fe₇₅B₂₅ Fe₆₇B₃₃) were studied comparatively with various sliding speeds. The friction coefficient of the Fe-B alloy changes slightly with the boron content. The wear rate of the Fe_94.3B_5.7 alloy with about 30 vol. dendrite t-Fe₂B is only one third of Fe ₇₅B₂₅ alloy with 15 vol. dendrite and Fe ₆₇B₃₃ alloy with 90 vol. dendrite in the high sliding speed. First, a hard t-Fe₂B phase reduced the wear of the Fe-B alloy directly. Second, the compactly oxide layers resulting from oxidation of the -Fe on the worn surfaces also decreases the wear rate of Fe-B alloys. On the whole, the wear rate of the Fe_94.3B_5.7 is lower than Fe ₆₇B₃₃ and Fe₇₅B₂₅.