Preparation method of long-period stacking order (LPSO) structural phase enhanced magnesium gadolinium zinc calcium aluminium alloy plate

Abstract

The invention relates to a preparation method of a long-period stacking order (LPSO) structural phase enhanced magnesium gadolinium zinc calcium aluminium alloy plate. The preparation method is aimed at the problem that an LPSO structural phase is hard to form in a cast magnesium gadolinium zinc alloy. The preparation method comprises the steps that calcium and aluminium elements are doped in the magnesium gadolinium zinc alloy, vacuum melting, argon bottom blowing protection and casting ingot forming are adopted, forming of the LPSO structural phase is induced, and a cast LPSO structural phase enhanced magnesium gadolinium zinc calcium aluminium alloy ingot is prepared; and an LPSO structural phase enhanced magnesium gadolinium zinc calcium aluminium alloy plate enhanced product is prepared through vacuum hot extrusion aging. The preparation method is advanced in technology, data is accurate and detailed, purity of the product is good and reaches 99.6%, strength reaches 417 MPa, elongation is 12%, corrosion voltage of the cast magnesium gadolinium zinc calcium aluminium alloy is minus 0.447 V, corrosion current density is 5.528 * 10<-6> A/cm<2>, corrosion voltage is improved by 3 times and corrosion rate is decreased by 500 times compared with those of the alloy in which Ca and Al are not added.

Description

technical field [0001] The invention relates to a preparation method of a long-period ordered stacking structure phase-reinforced magnesium-gadolinium-zinc-calcium-aluminum alloy plate, which belongs to the technical field of preparation and application of nonferrous metal materials. Background technique [0002] Long-period stacking order, LPSO has high hardness, high elastic modulus, high thermal stability, and has a coherent interphase interface with the magnesium matrix, which can significantly improve the strength, plasticity, and corrosion resistance of magnesium alloys However, it is difficult for magnesium-gadolinium-zinc alloys to form LPSO phases in the as-cast state, and the LPSO phase can only be formed after a long time of high-temperature solution treatment; while the brittle β-( MgZn) 3 The Gd phase is often distributed in the grain boundary in the form of a coarse continuous network / skeleton, splitting the matrix of the magnesium alloy and deteriorating the ...

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Problems solved by technology

[0002] Long-period stacking order, LPSO has high hardness, high elastic modulus, high thermal stability, and has a coherent interphase interface with the magnesium matrix, which can significantly improve the strength, plasticity, and corrosion resistance of magnesium alloys However, it is difficult for magnesium-gadolinium-zinc alloys to form LPSO phases in the as-cast state, and the LPSO phase can only be formed after a long time of high-temperature solution treatment; while the brittle β-( MgZn) 3 The Gd phase is often distributed in the grain boundary in the form of a coarse continuous network / skeleton, which splits the magnesium alloy matrix and deteriorates the material properties

[0003] At present, the CN 104178713 A patent has announced "a method for regulating and preparing the LPSO phase in the MgGdErZnZr alloy". After multi-step high-temperature solution heat treatment, the eutectic (MgZn) 3 The Gd phase is transformed into an LPSO phase, but the process is complicated, the production cycle is long, and the energy consumption is high; the size of the generated LPSO phase and the magnesium matrix unit cell is large, and the strengthening effect is weakened; The preparation method of MgGdZn(Zr) alloy", through the control of the solidification rate during alloy casting, the X phase at the grain boundary of the magnesium alloy and the intragranular LPSO structure coexist, but there are also a small number of X phases formed, most of which are (MgZn) 3 Disadvantages still existing in Gd grain boundary eutectic phase

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