Preparation method of multilayer composite modified layer with strong toughness on titanium alloy surface

Abstract

The invention relates to a preparation method of a multilayer composite modified layer with strong toughness on a titanium alloy surface, belonging to the technical field of surface modification and strengthening of metal materials. The invention is characterized by being a technical scheme that unit diffusion of Mo and co-diffusion of Mo / N are alternately and cyclically carried out on the surface of a titanium alloy substrate to prepare the Mo / MoN multilayer composite modified layer with strong toughness. The preparation method comprises the following steps: firstly, coating a Mo bottom layer with the thickness of 4-6 mu m by diffusion on the surface of a workpiece; then simultaneously introducing argon and nitrogen and coating a MoN layer with the thickness of 2-4 mu m by diffusion on the surface of the workpiece; cutting off the nitrogen supply, only introducing argon into a vacuum chamber, and continuing to coating a Mo layer with the thickness of 2-4 mu m by diffusion on the surface of the workpiece; by turning on and cutting off the nitrogen supply, continuing to alternately and cyclically coating MoN layers and Mo layers by diffusion on the surface of the workpiece, and enabling the most superficial layer of the multilayer composite layer to be the MoN layer to prepare the Mo / MoN multilayer composite layer with the modulation period of 2-4 mu m and the total thickness of 10-50 mu m; and taking out the workpiece after the workpiece cools in a furnace to the room temperature. The prepared Mo / MoN multilayer composite modified layer obviously improves the wear resistance of the titanium alloy under the high contact load condition.

Description

technical field

[0001] The preparation method of the toughness and toughness multilayer composite modified layer of the titanium alloy surface of the present invention belongs to the technical field of metal material surface modification and strengthening, and particularly relates to a method for preparing a high bonding strength, toughness and toughness Mo / MoN multilayer composite on a titanium alloy substrate Method for modifying layers. Background technique

[0002] Titanium alloy has the characteristics of high specific strength, good thermal stability, and excellent corrosion resistance. It is used in aerospace, chemical industry, biomedicine, automobile manufacturing, sporting goods and other fields. However, the wear resistance of titanium alloy is poor, which affects the safety and reliability of titanium alloy components and limits its application range. The use of surface engineering technology to form a modified layer on the surface of titanium alloy is an effect...