Abstract

The tribological behaviors of in situ–formed TiAl-TiB₂ composites were investigated from room temperature to 800 °C in low-pressure oxygen and related to their hardness and partial tribo-oxidation behaviors on the frictional surface. The wear resistance of TiAl-TiB₂ composites in low-pressure oxygen is significantly enhanced when the TiB₂ content increases from 0 to 20 vol% but decreases with a further increase in TiB₂ content to 30 and 40 vol%. The wear rates of the TiAl-TiB₂ composites are low below 200 °C and increase within 400–600 °C due to their decreased hardness and reach minimum values at 800 °C. The hardness of the composites and the degree of surface tribo-oxidation codetermine the wear resistance.

摘要

研究了原位形成的 TiAl-TiB ₂复合材料在低压氧气中从室温到 800 °C的摩擦学行为，并与它们的硬度和摩擦表面的部分摩擦氧化行为有关。当TiB ₂含量从0 vol%增加到20 vol%时，TiAl-TiB ₂复合材料在低压氧气中的耐磨性显着提高，但随着TiB ₂含量进一步增加到30和40 vol%而下降。TiAl-TiB ₂的磨损率复合材料在 200 °C 以下时低，并在 400-600 °C 内增加，因为它们的硬度降低，并在 800 °C 时达到最小值。复合材料的硬度和表面摩擦氧化程度共同决定了耐磨性。