An alloy preparation method for improving the microstructure of 2618 aluminum alloy

Abstract

The invention belongs to the field of aluminium alloy material preparation, and particularly relates to a preparation method of an alloy for improving a 2618 aluminium alloy microscopic structure, and the method includes the steps of refining a 2618 aluminium alloy as-cast grain structure and improving an as-cast structure pattern. The preparation method adopts the technical scheme that the preparation method comprise the steps of adding a certain amount of good-wettability Al-90Cu (Al-90wt%Cu) alloy powder to an aluminium alloy fusant to substitute an Al-Cu intermediate alloy used in the traditional casting process, strictly controlling temperature and mixing time of an aluminium alloy solution, immediately conducting near liquidus casting on the aluminium alloy solution when the powder is just dissolved, and obtaining a 2618 aluminium alloy with fine grains and decreased pine-tree crystals.

Description

technical field [0001] The invention belongs to the field of aluminum alloy material preparation, and particularly relates to an alloy preparation method for improving the microstructure of 2618 aluminum alloy, which includes refining the as-cast grain structure of 2618 aluminum alloy and improving the morphology of the as-cast structure. Background technique [0002] The 2618 aluminum alloy belongs to the Al-Cu-Mg-Fe-Ni heat-resistant forged aluminum, and the semi-coherent S`(Al 2 CuMg) phase is the main strengthening phase of the alloy, and the addition of a small amount of Fe and Ni in the same proportion can form intermetallic compounds such as Al 9 FeNi effectively controls the grain size and dislocation movement, further improves the room temperature and high temperature properties of the alloy, and is widely used in automobile manufacturing, aviation, aerospace and other fields. [0003] With the development of science and technology and aviation industry, higher req...

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Problems solved by technology

[0003] With the development of science and technology and aviation industry, higher requirements are put forward for the structure and performance of 2618 aluminum alloy, and the alloy with fine equiaxed grain structure is the key to improve the performance of the alloy at room temperature and higher temperature One; the method of refining the aluminum alloy matrix grains can be divided into two main types: one is to achieve the purpose of refining the grains by controlling and adjusting the alloy composition, cooling rate, and pouring temperature; the other is to solidify fine grains by adding The nucleating agent or microalloying method introduces a large number of foreign heterogeneous nucleation particles to obtain fine grains, that is, metamorphic fine grains; solidification of fine grains usually requires the help of a certain external electric field, magnetic field, and mechanical field. The requirements for equipment are high and the cost increases; while the modified fine grain usually has strict requirements and control on the amount of modified agent and the melt temperature, which not only increases the cost but also complicates the process, and even brings inclusion particles due to the addition of foreign particles. Improper control will seriously deteriorate the performance of the alloy; the patent applicant once added Al-90Cu alloy powder to die-cast zinc alloy to form a reinforcing phase, thereby preparing a zinc alloy-based composite material with good comprehensive properties

[0004] When the aluminum alloy is prepared by melting and casting, the traditional method is to add the required alloying elements in the form of various master alloys; because the intermetallic compounds in the master alloy are in a relatively coarse form and have large component segregation, so the method is adopted When this kind of master alloy is smelted into aluminum alloy, it will produce bad structure heredity, so that the dendrites in the obtained aluminum alloy structure are relatively developed and the grains are relatively coarse; therefore, it is necessary to find a new method of adding master alloy to replace the traditional one. The addition method of the master alloy, on the basis of ensuring the main components of 2618 aluminum alloy, prepares 2618 aluminum alloy with fine grain structure in the as-cast state, which has very important practical application value and is also an important innovation in the preparation method of aluminum alloy

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