Influence Of Interfacial Strength On Tensile Strength Properties Of Continuous SiC_f/Al Composites

The interface plays an important role in the fiber-reinforced metal-matrix composites,It is not only the bond between the reinforcing phase and the matrix in the fiber-reinforced metal-matrix composites,but also the bridge between the stress and other information.It is obvious that the properties of this kind of composite materials will depend heavily on the interfacial properties.Therefore,to obtain the excellent performance of continuous fiber reinforced aluminum matrix composites,there is the problem of interface optimization.Therefore,the influence of the interfacial strength of the composites is analyzed,Establish a quantitative characterization of the interface strength of the testing technology and the relationship between interfacial strength and macro properties of Aluminum Matrix Composites,It is of great significance to further promote the interface optimization and engineering application of continuous SiC_f/Al Composites.This paper is on the basis of the single fiber pull-out test and fiber push-out test,through the way of vacuum pressure infiltration,The single bundle pull-out test method for the interfacial strength of single bundle SiC_f/Al composites was studied.The effect of the temperature and matrix aluminum alloy on the interfacial strength of single fiber SiC_f/Al composites was investigated,Furthermore,the influence of interfacial strength on the tensile strength of the composites was investigated.The main conclusions are as follows:Single fiber pull-out test of single bundle SiC_f/Al composites was carried out by using Instron5543 type single vertical tensile testing machine,The fiber pull-out length under different conditions was obtained,Pull off occurs at the interface between matrix and fiber,is the interfacial strength of reaction,The Interfacial strength of fiber/matrix in continuous SiC_f/Al composites can be characterized by the single fiber pull-out,In particular,the test of weak interfacial strength is more effective and simple.The preparation parameters of SiC_f/Al composites(fiber preheating temperature)and the properties of matrix alloys have a significant effect on the interfacial strength of composites.The matrix alloy can effectively change the interface strength between the fiber and matrix in the continuous SiC_f/Al composites,and has obvious effect on the tensile strength of the continuous SiC_f/Al Composites;Single beam continuousSiC_f/Al composites with ZL301 as matrix,The interface strength and tensile strength are the largest,1.8MPa~2.7MPa and 235MPa;Single beam continuous SiC_f/Al composites based on ZL102 and ZL210 A,The interfacial strength and tensile strength were not significant,respectively,0.58MPa~0.87 MPa,157MPa and 0.65MPa~0.98 MPa,154MPa.At the same time,the SEM analysis of the extracted SiC fiber in the composite also found that the aluminum alloy has a significant effect on the morphology of the fiber surface:The surface of the fiber extracted from SiC_f/ZL102 composites is smooth,and the surface has a small interface attached to the fiber surface,its size is small and relatively dispersed;The fibers extracted from the SiC_f/ZL210 A composites surface have more interface attached to the fiber surface,Larger size and more concentrated;The fibers extracted from SiC_f/ZL301 composites are very rough and there are a large number of surface attached to the fiber surface,It also reflects the degree of interfacial reaction from the side.The preheating temperature of fiber is the key parameter in the process of vacuum impregnation of continuous SiC_f/Al composites.The interface strength between fiber and matrix can be adjusted effectively by changing the preheating temperature,With the increase of the preheating temperature,the interfacial strength increases gradually,Among them,500 ? and 530 ? the interfacial strength are0.54MPa~0.81 MPa,1.8MPa~2.7MPa,When the preheating temperature rises to 550?,the interfacial strength is further improved;The tensile strength of the composites reached the maximum at 530 ? is 232 MPa,The tensile strength decreases to the minimum when the preheating temperature of the fiber rises to 550?,it is 118 MPa.At the same time,the SEM analysis of the extracted SiC fiber in the composite was also found:Fiber preheating temperature has a significant effect on the morphology of fiber surface,With the increase of the preheating temperature,the surface morphology of the fibers gradually changed from the smooth surface to the rough surface,and the surface attachment of the fiber was from only a small amount of tiny spots to a large number of spots and lumps,It also reflects the degree of interfacial reaction from the side.