Views: 1 Author: Site Editor Publish Time: 2022-09-06 Origin: Site
In order to make up for the poor high temperature strength and low oxidation resistance of pure molybdenum alloy, producers often dope appropriate amount of additives such as zirconium hydride, yttrium oxide and cerium oxide in their production process, so as to make the produced The application range of the product is wider. The steps to produce molybdenum-based alloys using micro and nanotechnology are described below:
1) First prepare raw materials: zirconium hydride, carbon powder, titanium carbide (size between 0.1-0.6um), cerium oxide (size between 10-40nm) and yttrium oxide in weight ratios of 0.2%-0.6%, 0.1%-0.6%, 0.5%-2.0%, 0.5%-1.5% and 0.3%-0.8%, the rest is molybdenum.
2) Homogenization: Add zirconium hydride, carbon powder, titanium carbide, cerium oxide and yttrium oxide to the molybdenum powder matrix in a predetermined amount, and then put all the materials into the mixer and mix thoroughly.
3) Pressing: put a predetermined amount of the mixture material after homogenization in step 2) into the rubber sleeve and put it into an isostatic press together with the rubber sleeve for pressing, and the pressure value is kept between 180 and 220 MPa for at least 4 Minutes to take out the pressed workpiece.
4) Sintering: Put the pressed workpiece into a vacuum intermediate frequency furnace or a hydrogen furnace for sintering, and the sintering temperature gradually rises to between 1900°C and 2000°C and keeps it for 3-4 hours to obtain the desired product.
The homogenization step of the production method also includes taking out a predetermined amount of zirconium hydride, carbon powder, titanium carbide and rare earth oxides, then taking out molybdenum powder twice the total weight of the molybdenum powder for preliminary mixing, and finally mixing the initially mixed The material is added to the molybdenum powder matrix.
The reason why nano-scale rare earth elements are added to molybdenum-based alloys during production is to strengthen the solid solution to form a dispersed carbide phase, which in turn improves the bonding force of the solid solution crystal lattice to enhance the hardness, strength and plasticity of the alloy.