Method for detecting interface bonding strength of composite materials

Abstract

The invention discloses a method for detecting the interface bonding strength of composite materials. The method comprises the following steps: preparing two composite materials to be detected, an aluminum plate to be soldered and a filler; arranging the two composite materials to be detected, the aluminum plate to be soldered and the filler to form a three-layer structure: placing the aluminum plate to be soldered and the filler between the two composite materials in parallel, and allowing a part of the aluminum plate to be soldered to stretch out of the two composite materials; arranging the two composite materials in a thin metal layer facing manner; soldering the two composite materials, the aluminum plate to be soldered and the filler to obtain a soldered member; and drawing the soldered member until the soldered member is pulled and broken, recording the value of measured force, and calculating the thin metal layer and substrate interface bonding strength, wherein the thin metal layers of the composite materials, between the aluminum plate to be soldered and the filler, are removed. A sample produced through double side soldering is adopted to detect in order to make two forces applied to the thin metal layers be applied in the same plane and make the steel base and the aluminum alloy layer of the broken sample have no bended angles, so the measured value is accurate.

Description

technical field [0001] The invention relates to a method for detecting the interface bonding strength of a composite material, in particular to a method for measuring the interface bonding strength of an ultra-thin composite layer and other substrates. Background technique [0002] At present, aluminum-steel composite materials for brazed heat exchangers are composite materials made of bimetallic composites of aluminum and steel. Between aluminum and steel, the interfacial bonding strength of aluminum and steel is the key performance index for evaluating aluminum-steel composite materials. However, due to the very thin thickness of the cladding aluminum layer, conventional methods such as tension shearing, tearing, and compression shearing are used to evaluate the interfacial bonding strength. Layers will break and be difficult to evaluate. [0003] Glue bonding and single-sided brazing are commonly used in the prior art to quantitatively detect (that is, accurately detect)...

AI Technical Summary

Problems solved by technology

However, both the composite material 10 and the aluminum plate 20 to be brazed will be deformed during the tensile-shearing process, forming a bending angle at the fracture, and the sample will eventually be Figure 4 state shown

During the tension-shear process of single-sided brazing, the thin metal layer is subjected to the shear force along the bonding interface and the peeling force perpendicular to the bonding interface at the bonding interface. The interface bonding strength is composed of the shear force and the peeling force. The shear force The size and direction of the peeling force are related to the bending angle, and the bending angle is related to the thickness of the composite material, the thickness of the brazing layer and the bonding strength of the composite material interface. Therefore, among many influencing factors, the analysis of the shear force on the bonding interface Complicated calculations, many influencing factors and inaccurate results, it is difficult to conduct comparative analysis between materials with different thicknesses, and it is difficult to meet the requirements of precise experimental measurement and comparative research

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