The fatigue cracking behavior of ultra-high strength steels containing rectangular inclusions of small sizes were investigated based on in situ observations by scanning electron microscopy (SEM). The size and shape ...The fatigue cracking behavior of ultra-high strength steels containing rectangular inclusions of small sizes were investigated based on in situ observations by scanning electron microscopy (SEM). The size and shape of rectangular inclusions affect markedly the initiation site and propagation path of a fatigue crack. Especially, the initiation site of a fatigue crack depends strongly on the angle between the long-axis of a rectangle inclusion and the loading direction, and the length/width ratio of this rectangle inclusion because the residual stress distribution fields vary with these conditions. The results coincide very well with those of finite element analysis.展开更多
The mechanical properties and deformation mechanisms of unidirectional carbon fiber reinforced magnesium composites under tensile loading are studied. Two different materials are used as fiber coatings: a single sili...The mechanical properties and deformation mechanisms of unidirectional carbon fiber reinforced magnesium composites under tensile loading are studied. Two different materials are used as fiber coatings: a single silica and a gradient C/SiC/SiO[sb 2]. The results show that, under the same preparation conditions, composite with the former coating is broken in a non-cumulative mode and its failure stress is rather low. Conversely, the latter coating demonstrates much better efficiency and the corresponding composite is broken in a cumulative mode.展开更多
文摘The fatigue cracking behavior of ultra-high strength steels containing rectangular inclusions of small sizes were investigated based on in situ observations by scanning electron microscopy (SEM). The size and shape of rectangular inclusions affect markedly the initiation site and propagation path of a fatigue crack. Especially, the initiation site of a fatigue crack depends strongly on the angle between the long-axis of a rectangle inclusion and the loading direction, and the length/width ratio of this rectangle inclusion because the residual stress distribution fields vary with these conditions. The results coincide very well with those of finite element analysis.
文摘The mechanical properties and deformation mechanisms of unidirectional carbon fiber reinforced magnesium composites under tensile loading are studied. Two different materials are used as fiber coatings: a single silica and a gradient C/SiC/SiO[sb 2]. The results show that, under the same preparation conditions, composite with the former coating is broken in a non-cumulative mode and its failure stress is rather low. Conversely, the latter coating demonstrates much better efficiency and the corresponding composite is broken in a cumulative mode.