Method for preparing mg/mg2si composite material from plant ash

Abstract

The invention provides a method for preparing an Mg / Mg2Si composite material by using plant ashes. The method comprises the following steps of: step 1, weighing the plant ashes, and separately compressing the plant ashes into small pieces; step 2, drying and preheating pure magnesium and the plant ashes; step 3, melting the pure magnesium and subsequently adding the plant ashes; and step 4, refining, reserving the temperature, standing and casting so as to obtain the Mg / Mg2Si composite material. The method is used for preparing the Mg / Mg2Si composite material from the plant ashes, and in the process, the addition of silicon element is realized by adding the plant ashes; and the method has the characteristics of high efficiency, low cost and the like, is simple to operate and environment-friendly. The absorption rate of the silicon element can be more than 80%.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to a method for preparing Mg / Mg by using plant ash 2 Si composite method. Background technique [0002] Magnesium-based composites have attracted more and more attention due to their excellent physical and mechanical properties. And Mg / Mg 2 Due to the high temperature strengthening phase Mg contained in the Si composite material 2 Si, the strengthening phase has a higher melting point (1085°C) and hardness (460HV0.3), and a low density (1.9g / cm 3 ), high modulus of elasticity and low coefficient of thermal expansion (7.5×10 -6 K -1 ), coupled with the low cost of silicon, silicon becomes one of the preferred additive elements for the preparation of magnesium-based composites. [0003] However, due to the high melting point of silicon (1411°C), the property is quite different from that of magnesium liquid, and the wettability is not very good. How to dissolve silicon ...

AI Technical Summary

Problems solved by technology

However, there are inevitably the following disadvantages: (1) Crystalline silicon is usually produced by reducing silicon dioxide with carbon in an electric furnace, which not only consumes a lot of energy in the smelting process, but also has an impact on the environment

(2) When preparing the master alloy, the temperature of crystalline silicon is high when it is added to the melt, causing a large burning loss, and the absorption rate of silicon in this link is not high. (3) When smelting magnesium alloy, the remelting of the master alloy will cause Cause secondary burning and pollution, (4) Coarse primary silicon or primary Mg in the master alloy 2 The size of Si is relatively large, and the commonly used modification treatment methods are not suitable for primary silicon or primary crystal Mg. 2 Si has little effect, while coarse primary silicon or primary Mg 2 Si will be inherited into the ingot along with the casting process, thus affecting its properties

(5) If it is added in the form of Al-Si master alloy, the aluminum atoms in it will react with molten magnesium to form β-Mg which is easy to soften at high temperature 17 al 12 phase, which cannot effectively pin the grain boundaries at high temperatures, reducing the high temperature properties of the alloy

However, the in situ preparation of Mg / Mg using plant ash 2 A method for Si composites has not been reported so far

Images