Glass lubricant used for hot extrusion of titanium alloy and zirconium alloy as well as preparation method thereof

Abstract

The invention belongs to the field of a lubricant, and relates to the lubricant used for hot extrusion of a titanium alloy and a zirconium alloy as well as a preparation method thereof. The lubricantis composed of lubricant powder and soluble glass, the ratio of soluble glass to the mixed lubricant powder is 1:2-1:3, the lubricant powder comprises the following components: 60-80% of low-softeningpoint glass powder, 10-30% of SiO2 powder, 10-30% of NaCl powder, and the soluble glass with concentration being 1.0-1.1 mol/L. The lubricant has the advantage that the change of viscosity is small with temperature. The lubrication effect and thermal barrier effect are good, and cleaning is easy. The NaCl has water solubility, an extruding product attached with the lubricant is immersed into water, NaCl in the lubricant is dissolved in water, a porous structure is formed, and the lubricant is easily peeled from the surface of the product, and no pickling pollution is generated.

Description

Technical field: [0001] The invention belongs to the field of lubricants, and relates to a high-temperature lubricating material, in particular to a hot extrusion lubricant of titanium alloy and zirconium alloy and a preparation method thereof. Background technique: [0002] Titanium alloys and zirconium alloys have the characteristics of relatively low density, high specific strength, and excellent corrosion resistance, and are widely used in aerospace, defense and military industry, nuclear industry, sewage treatment, marine engineering and other fields. For example, zirconium alloy is currently the preferred material for nuclear reactor fuel cladding [1-2]. [0003] The application forms of titanium alloys and zirconium alloys mainly include pipes, profiles, bars, plates, etc. Among them, pipes, profiles, and bars are usually produced by extrusion, and for most profiles and pipes, extrusion is the only production method. [0004] Due to the high extrusion temperature, hi...

AI Technical Summary

Problems solved by technology

Among them, when pure copper is used to coat and extrude titanium alloys, since copper and titanium alloys are prone to react at high temperatures to form Ti-Cu eutectic products, the extrusion force increases, and subsequent pickling pollution is large[4]

When the zirconium alloy is lubricated with copper, there are problems that the copper skin is easy to break during the extrusion process, and the copper skin is not easy to remove [5]

[0006] Glass lubrication is currently the most advanced lubrication method for hard-to-extrude metals such as titanium alloys and ferrous metals. However, the viscosity of glass lubricants varies greatly with temperature, which leads to difficult process control in actual production, mold life, product quality and finished product quality. low rate issues

For example, the billet temperature is about 950°C during extrusion of titanium alloy, while the preheating temperature of die steel usually does not exceed 500°C, so there is a large temperature gradient between the billet and the die steel during extrusion, and the temperature gradient between the die steel and the die steel The temperature of the contact part is low, even lower than the softening point of the glass lubricant, which greatly reduces the lubricating effect

The current solution is to adopt a multi-layer coating method, that is, to coat the high softening point lubricant on the surface of the billet and to coat the low softening point lubricant on the mold surface, but correspondingly increases the production process and reduces the production efficiency

[0007] In addition, since the extrusion temperature of zirconium alloys is usually 200-300°C lower than that of titanium alloys, it is difficult for the existing glass lubricant materials for titanium alloy extrusion to be directly applied to the extrusion of zirconium alloys.