Detection method for interface bonding strength of particle reinforced metal matrix composite material

Abstract

The invention relates to a detection method for interface bonding strength of a particle reinforced metal matrix composite material. The method is characterized in that a mechanical processing method is firstly adopted to process a particle reinforced metal matrix composite material sample into a cuboid, wherein the cuboid is conveniently observed by a scanning electron microscope; a piece of the cuboid is cut along the shortest edge of the cuboid, and it is ensured that the two adjacent surfaces on the edge form an angle of 45 DEG after cutting; treatments of burnishing and polishing are performed on the two adjacent surfaces; under the scanning electron microscope, a loading head with a conductive adhesive performs stripping on the particles positioned on the 45 DEG edge of the sample in a vertical loading way, wherein the sample is fixed on an object stage during the stripping process; the stripped particles are adhered to the conductive adhesive to observe the morphology of the particles; concurrently the exact loading positions of the loading head on the particles are determined; the particle-matrix interface bonding strength is derived according to the stress simulation result of the loading process. The method of the present invention has strong adaptability, and can be used for interface bonding strength measurements of a plurality of composite materials, and the operation of the method is simple and convenient.

Description

technical field [0001] The invention relates to a detection method for the interfacial bonding strength of a composite material, in particular to a detection method for the interfacial bonding strength of a particle-reinforced metal matrix composite material. technical background [0002] Good interfacial bonding between the reinforcement and the matrix is ​​one of the necessary conditions for obtaining high-performance composite materials. For composite materials, it is very important to improve the interfacial bonding through appropriate preparation methods. Particle-reinforced metal matrix composites are low-cost and comprehensive. The characteristics of good performance and excellent electrical and thermal conductivity have attracted extensive attention from material researchers; there are two main methods for preparing particle-reinforced metal matrix composites: casting method and powder metallurgy method; for casting method, due to the ceramic particles and The wettab...

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Problems solved by technology

[0002] Good interfacial bonding between the reinforcement and the matrix is ​​one of the necessary conditions for obtaining high-performance composite materials. For composite materials, improving the interfacial bonding through appropriate preparation methods can It is very important. Particle reinforced metal matrix composites have the characteristics of low cost, good comprehensive performance, and excellent electrical and thermal conductivity, and have attracted extensive attention from material researchers. There are two main methods for preparing particle reinforced metal matrix composites: casting method and powder metallurgy; for the casting method, it is difficult to form a good interface bond due to the poor wettability between the ceramic particles and the molten metal. reaction, resulting in a decrease in the interface bonding strength; for conventional powder metallurgy methods, the interface bonding status usually depends on the hot pressing temperature and pressure. A large number of experiments have shown that it is difficult to ensure the formation of a high bonding strength interface only by optimizing the parameters of the hot pressing process. At the same time, the oxides on the surface of the metal powder are not conducive to the bonding of the interface.

[0003] An important means of characterization of the interfacial bonding of composite materials is the detection of interfacial bonding strength of composite materials. Pull-out method, ejection method, ultrasonic method, etc., such as single-fiber ejection method, the basic process is: determine the position of the ejected fiber under the microscope, and then slide to the right under the diamond probe, and slowly adjust the position of the fiber. An axial load is applied to the end until the fiber is debonded from the surrounding matrix carbon, and the load Pd at the time of debonding is recorded, and then the diameter ( D ) of the fiber and the thickness ( H ) of the sample are measured, However, these methods are not suitable for particle reinforced composites, mainly due to the particularity of particle reinforcements, small size and isotropy, it is difficult to detect the interface bonding strength of fiber reinforced composites by the usual method. The interfacial bonding strength of materials is mainly measured indirectly, that is, the interfacial bonding strength is estimated by measuring the macroscopic mechanical properties

[0004]Sánchez et al. (Sánchez J M, el-Mansy S, Sun B, et al. Cross-sectional nanoindentation: a new technique for thin film interfacial adhesion characterization. Acta Materialia , 1999, 47(17): 4405~4413.) The nano-indentation method for interfacial bonding strength of coatings proposed has a certain reference effect on the detection of interfacial bonding strength of composite materials. The basic process of this method is to insert the nano-indenter Acting directly on the interface, the parameter that characterizes the interface bonding strength is the critical load of interface cracking. This method is more suitable for thicker coatings, but not suitable for thinner coatings, because for too thin coatings, It is not easy to control the center position of the indenter on the interface. When the indentation method is used to measure the interface bonding strength, there are at least two shortcomings: First, the stress state near the indenter is very complicated, and the edge effect produced makes it difficult to accurately measure the bonding strength of the interface. According to the existing results, researchers have used fine enough grid density near the indenter to make up for this deficiency. Second, when the measurement object is a brittle coating, Sometimes the interface has not yet cracked, but the coating itself cracks first. If this happens, it will bring the complexity of theoretical modeling to the calculation of the interface bonding strength using finite elements. For example, the coating must be considered when modeling. The dynamic three-dimensional crack expansion model calculates the change of the interface stress field caused by the dynamic expansion of the coating crack and the corresponding stress state on the interface when the interface cracks instantaneously. For the interface that has not yet cracked due to the interface bonding strength In the case that the coating cracks first, the indentation method can also evaluate the interfacial bonding performance of the material system from a qualitative point of view, such as given parameters such as the position of the indentation point, the shape of the indenter, and the magnitude of the load to compare the resulting The length of the interface crack

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