Effect Of Space Structure On Failure Mechanism Of Steel Matrix Composites

Ceramic particle reinforced metal matrix composites have been paid much attention to,but the toughness and plasticity of the materials are greatly reduced while the strength and hardness of the composites are improved,and the structural design has a prominent advantage in solving this kind of problem.The research group has done a lot of research on the toughening of three-dimensional interpenetrating MMCs.On this basis,this paper focuses on the static pressure,pressure and pressure fatigue properties of the cylindrical 3D-MMCs/steel composite with the optimal three-dimensional structure and the failure fracture mechanism of the material under the two types of testing,and the homogeneous composite under the same test environment.In terms of performance and fracture,from a scientific point of view,a solid and effective basis for improving the design and improvement of space structure composite materials is provided to enrich the theory of composite design.In this paper,90-120 mesh ZTA ceramic particles are selected as the reinforced body,and the solid 40 Cr is used as the metal matrix to design and prepare the cylindrical 3D-MMCs/steel composite and uniform composite.The static pressure test of two kinds of materials shows that the tensile strength of the composite is1025.67 MPa and the strain rate is 0.419%.The compressive strength of the composite material is 987.41 MPa,and the strain rate is 11.3 when the compression limit is limited.Compared to the linear elastic phase to the compression limit,the compressive strength of the composite material has a rapid landing,showing the characteristics of completely brittle materials.The compressive strength of the composite material increases after the end of the elastic phase of the 600 MPa and the left and right lines.It shows a good elastoplastic characteristic,and the two kinds of material static pressure failure gap and crack analysis show that the design of space structure effectively restricts the development of crack and fully exerts the excellent ductile and ductile deformation ability of the ductile steel base.3D-MMCs/steel composites and homogeneous composites were tested under the pressure-pressure fatigue testing environment of 500 MPa amplitude and 20 HZ frequency to test the fatigue failure of materials.The results show that the fatigue cycle of the composite material is higher than that of the homogeneous compositematerial 8~0 times,and it is different from the homogeneous composites along the tangential fracture.The spatial structure composite is broken in the direction of the vertical load of the composite continuous surface,and there is no typical fatigue crack propagation trace in the fracture surface.Therefore,the design of the space structure has great effect on improving the plasticity and fatigue resistance of the material,and the fine deformation ability of the ductile steel base block gives the material good notch low sensitivity.The structural failure mechanism provides a solid theoretical basis for the improvement of the space structure composite material.