A surface strengthening and toughening treatment process of aluminum extrusion die

Abstract

The invention relates to an aluminum extrusion die and its surface strengthening and toughening treatment process. The process aims to improve surface strengthening and toughening performance of the aluminum extrusion die. By a two-stage process of doping of N before multi-element penetration of O-S-N, thicknesses of a strengthened layer and a diffusion layer in a penetration layer are both increased at different levels in comparison with an isothermal method, and it is ensured that bonding ability of the penetration layer and a matrix is better. Hardness gradient of the penetration layer is milder, penetration layer peeling time is put off, and life of the die is effectively prolonged. In addition, based on the two-stage process, thickness and strength of the diffusion layer are both raised effectively by the use of a Ce / La rare earth compound for catalysis and by the use of an NH4Cl powder for cleaning and penetration treatments; and an antifriction complex phase layer containing Fel-xS and Fe3O4 phases and a strengthened layer containing Fe2-3N, gamma'-Fe4N and other high hardness and toughness phases can be obtained. Thus, the penetration layer satisfies ideal wearing layer conditions of tribological requirements.

Description

technical field [0001] The invention relates to the technical field of dies, in particular to a surface strengthening and toughening treatment process of an aluminum extrusion die. Background technique [0002] Relevant studies at home and abroad have shown that the use of surface toughening treatment for aluminum extrusion dies is one of the most effective methods to improve their performance and prolong their service life. The cycle is long, and the nitrided layer is brittle, and it is easy to peel off during the extrusion process, causing defects such as scratches on the surface of the aluminum alloy profile, and excessive wall thickness and size. For this reason, related research at home and abroad has developed physical vapor deposition (PVD) Coating) method, ion nitriding, multiple ion composite method, O-S-N multi-component co-carburizing and soft nitriding method and other new surface strengthening and toughening treatment processes. [0003] At present, my country'...

AI Technical Summary

Problems solved by technology

However, the existing multi-component co-infiltration treatment process often has problems such as insufficient thickness of the diffusion layer and insufficient solid solution strengthening, microstructural defects such as vein-like grains, and steep hardness gradient distribution of the co-infiltration layer, which makes the co-infiltration strengthened layer It is easy to peel off during the extrusion production process, resulting in the scrapping of extrusion dies, etc.

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