1. Production methods of ammonium paratungstate include evaporation method, crystallization method, freeze-drying method and solvent extraction method.

Milling processing is divided into down milling and up milling. Down milling is a milling method in which the rotation direction of the contact part of the milling cutter and the workpiece is the same as the cutting feed direction.

There are four main production technologies of preparing tungsten copper: mixed-press sintering method, activation sintering method, infiltration method, and nano/ultrafine mixed powder sintering method.

1.Brief introduction

Barium tungstate is white powder, has micro toxicity. Relative density is 5.04. It can slightly dissolve in water, completely dissolved in oxalate water solution, decompose in acid and is stable in the air.

1.Brief introduction

Block infrared rays at 950nm (up to 95% at 1400nm), mainly used for various plastic and glass films.

There are four preparation methods of tungsten alloy balls, namely, compression molding, disc pelletizing, squeeze-cut rotation method and injection molding.

The low-temperature ductility of the tungsten wire is the main factor affecting the winding performance. The main influencing factors are the purity of raw materials, additives and the surface condition of the wire.

Impurity elements in tungsten alloys include H, O, C, N, P, S, and Si. Because these elements have small atomic radii, and strong diffusivity in alloys, they are more likely to be in the grain boundaries and phases.

The tip angle of the tungsten electrodes should be made according to the current selection.

The testing procedures of sagging value of tungsten wire includes shaping and testing results calculation.