High-volume-fraction ultrafine particle enhanced Mg-Li base composite material and preparing method thereof

Abstract

The invention discloses a high-volume-fraction ultrafine particle enhanced Mg-Li base composite material and a preparing method thereof, and belongs to the technical field of composite materials and preparing of the composite materials. The preparing method comprises enhanced body surface modification, flaky body forming through cold pressing, mixing cold-pressing forming with a flaky Mg-Li alloyand other procedures. Then under guidance of a guiding bar, multi-pass variable diameter angle hot extrusion is conducted, and an Mg-Li base composite material is obtained. By means of the high-volume-fraction ultrafine particle enhanced Mg-Li base composite material and the preparing method thereof, material forming and deforming are integrated, through variable diameter angle extrusion, the flaky Mg-Li alloy and an enhanced body prefabricated body are subjected to upsetting, shearing, drawing and other large-plasticity deformation, enhanced body particles are evenly distributed in the Mg-Lialloy, the content of the enhanced body is high, and the enhanced Mg-Li base composite material with the particle volume fraction being 10%-30% can be prepared. The Mg-Li base composite material is directly extruded and formed in a solid state or a semi-solid state. Compared with a traditional stirring casting technology, the operation process is short, energy is saved, and industrial production is facilitated.

Description

technical field [0001] The invention belongs to the technical field of composite materials and preparation thereof, and in particular relates to a high volume fraction ultrafine particle reinforced Mg-Li based composite material and a preparation method thereof. Background technique [0002] Magnesium-lithium alloy, as the lightest metal structural material, has high specific strength, specific stiffness, excellent shock absorption performance and high-energy particle penetration resistance, and has broad application prospects in aerospace, military equipment, transportation and other fields . However, magnesium-lithium alloys have intrinsic properties such as high component activity, low elastic modulus, and strength attenuation due to room temperature overaging, which limits the engineering preparation and wide application of alloys. Reference [1] ("Research Progress of Ultrafine Intermetallic Compound Particles Reinforced Mg-Li-Based Composite Materials", Wu Guoqing et a...

AI Technical Summary

Problems solved by technology

When using the stirring casting method to prepare magnesium-lithium-based composite materials, due to the high chemical activity of the matrix alloy elements Mg and Li, and the relatively high melting temperature, and the large surface energy of the ultra-fine reinforcement particles, they are easy to burn and oxidize, resulting in ultra-fine reinforcement. Bulk particles are difficult to add in a large volume fraction into the molten matrix alloy

Although the patent documents of publication numbers CN 102912159A and CN 104789841A add reinforcement particles to the molten matrix alloy in the form of prefabricated blocks, due to the high activity of ultrafine particles and residual air in the prefabricated blocks, it is easy to cause melt oxidation during smelting. , resulting in local bumping, splashing of the melt and the reinforcement, etc., it is difficult to accurately control the material components, which brings certain safety hazards to the smelting; and the above preparation method requires compound ball milling of reinforcement particles and magnesium powder, cold pressing, Hot pressing, hot extrusion and other steps, and finally the composite material is prepared by vacuum induction melting with the matrix alloy. The process is relatively complicated and requires a large amount of energy input

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