A method for predicting the mechanical properties of silver-based solder brazing joints regulated by low melting point elements

Abstract

The invention discloses a method for predicating the mechanical property of a brazing joint made of a low-melting-point element controlled silver-based brazing material. The method comprises steps as follows: S1, composition and a base metal material of the brazing material used by the brazing joint are determined, wherein the brazing material is a silver-based brazing material; S2, the content WM% of all low-melting-point elements in the silver-based brazing material is measured; S3, the melting temperature interval delta TM of the silver-based brazing material is determined; S4, the content WM% of different low-melting-point elements in S2 is amplified by 100 times, and the melting temperature interval delta TM of the silver-based brazing material in S3 are substituted into a prediction mathematical model SJ is shown in the description, wherein n is equal to 1, 2, 3,... and denotes one low-melting-point element, two low-melting-point elements, three low-melting-point element and so on in the brazing material; S5, the mechanical property of the brazing joint is judged according to the number value of S4, the larger the number value is, the better the mechanical property is, and otherwise, the smaller the number value is, the poorer the mechanical property is. The method is simple and feasible.

Description

technical field [0001] The invention belongs to the field of performance evaluation of brazing joints, in particular to a method for predicting the mechanical properties of silver-based solder brazing joints regulated by low melting point elements. Background technique [0002] As an important index for evaluating brazing process and application, the mechanical properties of solder joints directly affect the use of solder, the quality and performance of brazing joints, and further affect the service life and reliability of brazing parts. Therefore, the mechanical properties of brazed joints are one of the key issues in evaluating the usability of solder. [0003] Low melting point elements (melting point lower than 350°C) have the beneficial effect of reducing the melting temperature of solder and improving the wettability of solder. For silver-based solder with moderate melting temperature and excellent gap filling ability, adding a certain amount of low Melting point elem...

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Problems solved by technology

Chinese patent CN201410071437.4 discloses a method for testing the mechanical properties of brazed joints including force generation, acquisition and conversion, microscopic image amplification, acquisition and transmission, and data display and processing devices. The data is accurate, but a large number of joints need to be welded, tensile strength or Shear strength test, image processing analysis, etc., high cost, low efficiency, poor feasibility

CN201510056491.6, with the help of fusion ratio, energy asymmetric distribution rate, and ultimate tensile strength, a mathematical model for the mechanical properties of heterogeneous laser welding joints is established, which is the connection of nickel-based alloy / 304 austenitic stainless steel and the selection of energy asymmetric distribution rate Provides a feasible method, but requires multiple accuracy checks, optimization calculation of energy asymmetric distribution rate, huge data and low efficiency

CN201010173763.8 discloses a method for predicting the mechanical properties of Q345 welded joints based on artificial neural networks. With the help of welding current, voltage, welding speed and tensile strength, yield strength, reduction of area and elongation data, the welding process parameters and The mapping relationship between the mechanical properties of the joints, using the artificial neural network model to predict the mechanical properties of the welded joints, the disadvantage of this method is that the sample data is different, the neural network model is different, the joint performance prediction will change, and the limitation is relatively large

CN201611178243.X draws the brazing seam strengthening curve through the procedures and test data such as brazing bar stock, homogeneous bar stock, tensile test, base metal and brazing seam elastic modulus measurement. The disadvantage of this method is that there are many test data and the strengthening The accuracy of the curve drawing is not high, which affects the accuracy of the prediction of the mechanical properties of the brazing joint

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