Remanufacturing method for scrap titanium chips through ball milling-equal channel angularpressing

Abstract

The invention provides a remanufacturing method for scrap titanium chips through ball milling-equal channel angular pressing. The remanufacturing method sequentially comprises the step of recovering and pretreating titanium chips, the step of performing ball milling treatment on the titanium chips, the step of loading the titanium chips into an equal channel angular pressing mold, the step of performing preprocessing at a room temperature through the equal channel angular pressing, the step of curing and processing at a high temperature, and the step of quenching. The ball milling-equal channel angular pressing composite technique provided by the invention is simple and practical to operate and high in controllability. Through remanufacturing, not only can nanometer block titanium materials (smaller than 200nanometers) with full densification be obtained, but also the metallurgical defect of the continuous distribution and gathering of large sliced oxides can be eliminated. In addition, the shapes of the titanium chips are refined and reformed, and anisotropy caused by deformation texture in hexagonal close packed titanium materials is restrained. The yield strength of the remanufactured nanometer titanium materials reaches to the level of 5-grade titanium, the distribution of nanometer particles of the oxides presents a dispersed uniform state, and through the isotropy of the properties of the materials, the remanufacturing of scrap titanium resources for value increase at low cost is realized.

Description

technical field [0001] The invention relates to the solid-state recycling and remanufacturing technology of waste titanium chips, in particular to a method for recycling waste titanium chips by adopting a ball milling-equal channel angular extrusion method. Background technique [0002] The recycling and remanufacturing of scrap metal resources is one of the key factors for achieving sustainable development. Titanium (Ti) is a very important metal resource with high smelting costs. It has excellent biocompatibility, good corrosion resistance, and suitable mechanical properties. It is an important material for the manufacture of medical devices, artificial joints, and large energy and chemical containers. However, in order to manufacture high-precision titanium structures, a large machining allowance needs to be designed. A considerable proportion of the raw material will be converted into waste swarf. The traditional chip treatment technology is high-temperature melting an...

AI Technical Summary

Problems solved by technology

However, ECAP-treated Ti contains oxides (TiO 2 ), its texture is tough, although the oxide can be partially fractured after multiple passes of ECAP treatment, but the continuous distribution and aggregation of larger (mm-scale) sheet-like oxides in the microstructure is a serious metallurgical defect

At the same time, ECAP has a refinement limit, that is, when the dynamic recrystallization and strain refinement effects are balanced, it will be difficult for ECAP to refine the microstructure to the nanoscale (<200nm)

In addition, ECAP-treated (hexagonal close-packed) Ti is prone to deformation texture, i.e., material anisotropy due to preferred orientation of grains, which will weaken the (desired) isotropy of Ti properties

[0007] Although BM technology can be used to prepare ultra-fine powder materials, after BM treatment, sintering and other processes must be carried out to obtain large-sized bulk materials

In the subsequent sintering process, due to the influence of factors such as long-time (diffusion) heating and recrystallization, grain coarsening easily occurs in the ultra-fine structure, and it is difficult to ensure that the ultra-fine structure is still obtained (maintained) in the final bulk material. grain structure, resulting in loss of strength

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