Ultrahigh-pressure high-temperature synthesizing method of second-phase particle simulation material in aluminium alloy

Abstract

The invention discloses a method for preparing a second-phase particle simulation material in aluminium alloy under the ultrahigh-pressure high-temperature condition. The method comprises the steps that based on the chemical component stoichiometric ratio of second-phase particles in the aluminium alloy, pure metal powder is adopted for suppressing biscuits, GPa-grade high pressure is applied to an artificial diamond six-surface diamond presser, then the biscuits are heated to the high temperature, and the temperature is preserved for some time; finally, under the high-pressure keeping effect,the biscuits are cooled to the indoor temperature. By adopting the ultrahigh-pressure high-temperature synthesizing method, the simulation material with the phase same with the second-phase particlesin the aluminium alloy, accurate chemical components and sample size meeting the requirement of a conventional electrochemical test can be prepared, and therefore the foundation is laid for indirectresearch of the corrosion electrochemistry behavior of the second-phase particles in the aluminium alloy by adopting a simulated electrode method.

Description

technical field [0001] The invention belongs to the technical field of preparation of intermetallic compounds, and in particular relates to the preparation of second-phase particle simulation materials in aluminum alloys by means of an ultrahigh-pressure high-temperature synthesis method. Background technique [0002] Aluminum alloys usually contain various additive or impurity elements such as Zn, Mg, Cu, Si, Fe, Ni, Zr, Ti, etc. These elements often form different types of second-phase particles of intermetallic compounds during the aluminum alloy forming process, including micron-scale crystalline phases (such as AlFe, AlFeSi), submicron-scale dispersed phases (such as Al 6 Mn, Al 3 Zr) and nanoscale precipitates (such as MgZn 2 , Mg 2 Si, Al 2 Cu) and so on. These second-phase particles often lead to localized corrosion of aluminum alloys, for example, intergranular corrosion is closely related to precipitated phases at nanoscale grain boundaries, and micron-scale c...

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Problems solved by technology

However, the micro-area electrochemical testing technology has low measurement accuracy, low resolution, large environmental interference, and difficult preparation of nanoprobes, especially it is difficult to directly characterize the corrosion electrochemical behavior of nanoscale precipitates; the second is to use the simulated electrode method to indirectly characterize aluminum Corrosion electrochemical behavior of the second phase particles in the alloy, according to the chemical composition characteristics of the second phase particles, the corresponding simulated materials were prepared by casting, sintering, magnetron sputtering and other methods, and then tested by conventional corrosion electrochemical methods

The simulated electrode method has the advantages of simple test, small signal interference, and accurate test results. However, the difficulty lies in how to prepare simulated materials that can accurately reflect the properties and composition characteristics of the second phase particles and whose sample size is suitable for conventional electrochemical measurements. The simulated material has the same phase as the second phase particles, the chemical composition is accurate, and the sample size meets the test requirements (the cross-sectional size of the sample is above 1cm×1cm), etc.

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