CN101748300B

CN101748300B - Method for preparing Mg2Si reinforced magnesium matrix composites

Info

Publication number: CN101748300B
Application number: CN2010100458539A
Authority: CN
Inventors: 闫洪; 陈小会; 吴庆捷; 胡志
Original assignee: Nanchang University
Current assignee: Nanchang University
Priority date: 2010-01-19
Filing date: 2010-01-19
Publication date: 2011-11-16
Anticipated expiration: 2030-01-19
Also published as: CN101748300A

Abstract

The invention relates to a method for preparing Mg2Si reinforced magnesium matrix composites, which belongs to the field of the metal material preparation. The method comprises the following steps: firstly carrying out drying treatment on Si powders and using an aluminum foil to coat the Si powders, putting an AM 60 magnesium alloy ingot into a crucible to heat to melt down the ingot, and carrying out heat insulation at a temperature between 800 and 900 DEG C; extending an ultrasonic amplitude transformer into the magnesium alloy melt, and simultaneously using the aluminum foil to coat the preprocessed Si powders the mass fraction of which is between 0.9 and 1.1 percent and adding the coated Si powders into the melt, and carrying out ultrasonic processing for 10 to 30 minutes under the condition that the ultrasonic power is between 400 and 900 W; and reducing the temperature of the melt to 640 to 650 DEG C, continuously carrying out ultrasonic processing for 2 to 8 minutes in the process of reducing the temperature, and carrying out moulding and sampling. The crystal grains in the tissues of the Mg2Si/AM60 magnesium matrix composites are fine. The Mg2Si reinforced grains have small size and uniform distribution, has simple, safe and reliable process and convenient operation, and has no pollution of the three wastes.

Description

A kind of Mg＜sub〉2＜/sub〉Si strengthens method of preparing magnesium-based composite material

Technical field

The invention belongs to the metallic substance preparation field, particularly method of preparing magnesium-based composite material.

Background technology

Particle reinforced magnesium base compound material has specific tenacity, specific rigidity height, wear-resistant, high many advantages such as vibration damping.Mg ₂Si has high-melting-point, high rigidity, high Young's modulus and lower-price characteristic simultaneously again because of it has good thermoelectricity capability, is the ideal wild phase, by numerous scholars are paid close attention to.Mg and the spontaneous chemical reaction that carries out of Si meeting in the particle reinforced magnesium base compound material of in-situ reaction preparation, equation is: 2Mg (g)+Si (s) → 2Mg ₂Si (s).The matrix material that reaction in generates has characteristics such as interfacial bonding property is good, pollution-free, Heat stability is good, saving cost, thereby comes into one's own gradually.Yet Mg by the generation of original position casting technique ₂Si wild phase particle is thick, skewness, and the reaction times is longer, has hindered its further development.

Summary of the invention

The purpose of this invention is to provide and a kind ofly prepare Mg with the ULTRASONIC COMPLEX reaction in ₂Si strengthens the method for magnesium base composite material.

Preparation method of the present invention is: at first the Si powder is dried and handle and coat with aluminium foil, the AM60 magnesium alloy ingot is put into the crucible internal heating to fusing, and be incubated in 800 ℃～900 ℃ scopes.Ultrasonic amplitude transformer is stretched in the magnesium alloy fused mass, is that the good Si powder of pre-treatment of 0.9-1.1% coats with aluminium-foil paper simultaneously with massfraction, join in the melt, and be under the condition of 400W～900W at ultrasonic power, ultrasonic 10～30 minutes; Melt temperature is reduced to 640 ℃～650 ℃, in this process, continued ultrasonic 2～8 minutes, the casting sampling.

The Mg that the present invention obtains ₂Crystal grain is tiny in the Si/AM60 magnesium base composite material tissue, Mg ₂Si enhanced granule size is tiny and be evenly distributed, and technology is simple, safe and reliable, easy to operate, and three-waste free pollution.

Description of drawings

Fig. 1 is the Mg of the present invention's preparation ₂Si/AM60 magnesium base composite material microstructure.

Fig. 2 is the Mg of the present invention's preparation ₂Mg in the Si/AM60 magnesium base composite material ₂The distribution situation of Si.

Embodiment

The present invention will be described further by following examples.

Embodiment 1.

At first the Si powder is dried and handle and coat, the AM60 magnesium alloy ingot is put into the crucible internal heating to fusing, and be incubated 800 ℃ of scopes with aluminium foil.Ultrasonic amplitude transformer is stretched in the magnesium alloy fused mass, is that 1.0% the good Si powder of pre-treatment coats with aluminium-foil paper simultaneously with massfraction, join in the melt, and be under the condition of 400W at ultrasonic power, ultrasonic 30 minutes; Melt temperature is reduced to 640 ℃, in this process, continued ultrasonic 8 minutes, the casting sampling.

Embodiment 2.

At first the Si powder is dried and handle and coat, the AM60 magnesium alloy ingot is put into the crucible internal heating to fusing, and in 850 ℃ of scopes, be incubated with aluminium foil.Ultrasonic amplitude transformer is stretched in the magnesium alloy fused mass, is that 0.9% the good Si powder of pre-treatment coats with aluminium-foil paper simultaneously with massfraction, join in the melt, and be under the condition of 650W at ultrasonic power, ultrasonic 20 minutes; Melt temperature is reduced to 645 ℃, in this process, continued ultrasonic 5 minutes, the casting sampling.

Embodiment 3.

At first the Si powder is dried and handle and coat, the AM60 magnesium alloy ingot is put into the crucible internal heating to fusing, and in 900 ℃ of scopes, be incubated with aluminium foil.Ultrasonic amplitude transformer is stretched in the magnesium alloy fused mass, is that 1.1% the good Si powder of pre-treatment coats with aluminium-foil paper simultaneously with massfraction, join in the melt, and be under the condition of 900W at ultrasonic power, ultrasonic 10 minutes; Melt temperature is reduced to 650 ℃, in this process, continued ultrasonic 2 minutes, the casting sampling.

As shown in Figure 1, the Mg that under embodiment 2 conditions, obtains ₂Do not have tangible dendritic crystal state to occur in the Si/AM60 magnesium base composite material tissue, the substitute is a large amount of rosiness, spheric grain.The local overcooling phenomenon of growing up and causing of ultrasonic cavitation bubble makes too early some crystal grain of appearance in the melt, and these fine particles are broken in the collapse of cavitation bubble again, and by this a series of variation, the crystal grain of matrix material has obtained tangible refinement.

As shown in Figure 2, under high-energy ultrasonic, reaction has generated the newborn substance of a series of particulate state and Chinese character shape.The punctate substance of Sheng Chenging mainly is distributed in crystals as we can see from the figure, and granular size is about 10 μ m, and the novel substance of the Chinese character shape of generation does not have specific position.

As can be seen from the figure, the Mg that adopts the present invention to obtain ₂Crystal grain is tiny in the Si/AM60 magnesium base composite material tissue, Mg ₂Si enhanced granule size is tiny and be evenly distributed, and technology is simple, safe and reliable, easy to operate, and three-waste free pollution.

Claims

1. Mg ₂Si strengthens method of preparing magnesium-based composite material, it is characterized in that at first the Si powder being dried handling and coating with aluminium foil, the AM60 magnesium alloy ingot is put into the crucible internal heating to fusing, and be incubated in 800 ℃～900 ℃ scopes; Ultrasonic amplitude transformer is stretched in the magnesium alloy fused mass, is that the good Si powder of pre-treatment of 0.9-1.1% coats with aluminium-foil paper simultaneously with massfraction, join in the melt, and be under the condition of 400W～900W at ultrasonic power, ultrasonic 10～30 minutes; Melt temperature is reduced to 640 ℃～650 ℃, in this process, continued ultrasonic 2～8 minutes, the casting sampling.