Laser cladding composite coating on magnesium alloy surface assisted by ceramic-based buffer heat insulation layer and preparation method thereof

Abstract

The invention provides a ceramic-based buffer heat-insulation layer assisted laser cladding composite coating on the surface of a magnesium alloy and a preparation method thereof. The composite coating consists of three parts: a buffer heat-insulation layer, an auxiliary connection layer, and a surface protection layer; The buffer heat insulation layer is composed of two layers as the core layer of the composite coating. The first layer is composed of ceramics with a mass fraction of 50%-60%, metals with 33%-42% and rare earth oxides with 7%-8%. The second layer is composed of 84%-88% ceramics, 7%-8% rare earth oxides and 5%-8% rare earth magnesium alloy by mass fraction; the auxiliary connection layer is mixed metal powder and 1% by mass fraction. %-2% rare earth compound; the surface protective layer is composed of alloy powder with high melting point, high hardness and excellent wear resistance. The invention solves the difficulties such as holes and cracks often appearing in coatings and interfaces, limited selection of surface protective layers, and the like.

Description

technical field [0001] The invention relates to a composite coating and a preparation method thereof, in particular to a ceramic-based buffer heat insulation layer assisted magnesium alloy surface laser cladding composite coating and a preparation method thereof, belonging to the technical field of magnesium alloy surface modification. Background technique [0002] Magnesium alloy has the characteristics of high specific strength, high toughness, low density, good plasticity and impact toughness, and easy processing. It has broad application prospects in aviation, aerospace and other fields, but its hardness, wear resistance, and corrosion resistance are poor. It limits its scope of application in aerospace and aviation fields. As an emerging magnesium alloy surface modification technology, laser cladding technology has the characteristics of high coating preparation efficiency, strong bonding force between coating and substrate, and good coating compactness. However, the h...

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Problems solved by technology

It aims to eliminate the holes and cracks that often appear in the cladding process on the basis of meeting the requirements of high hardness and high wear resistance on the surface of magnesium alloys, and solve the adverse effects of thermal deformation and gasification and floating of magnesium alloys on the coating during laser cladding. , The problem of limited selection of magnesium alloy surface modification layer

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