中文摘要：

由于铱的高熔点、优异的高温强度和抗腐蚀性能,是能够在极端恶劣条件下使用的唯一金属。虽然铱具有面心立方晶体结构,但它的断裂模式却为脆性断裂（穿晶脆性断裂和沿晶脆性断裂的混合断裂模式）。自从20世纪60年代人们发现了铱的异常脆性断裂行为以来,就展开了大量的研究工作。然而至今,关于铱的致脆机制仍未被澄清。本文综述了铱可能的致脆机制：杂质致脆、本征脆性和特殊缺陷结构致脆,讨论了铱变形与失效机制的研究现状,并对未来研究的重点与手段进行了展望。

英文摘要：

Due to the high melting point, excellent high temperature strength and anticorrosive property, iridium is the unique material which can be used under extremely hostile environments. However, iridium exhibits an anomalous brittle fracture behavior, a mixed brittle intergranular fracture（BIF） and brittle transgranular fracture（BTF）, even though it is of face-centred cubic（fcc） crystal structure. A great deal of efforts have been made to explore the embrittlement mechanisms since the anomalous fracture behavior was recognized in 1960 s, up to now, there has not been a reasonable conclusion yet. This paper emphatically reviewed the possible embrittlement mechanism of iridium, including impurity-induced brittleness, intrinsic brittleness and special defect structure induced embrittlement, discussed the research status quo about the deformation and failure mechanisms of iridium. Finally, the research direction and research method of the embrittlement mechanism of iridium were forecasted.