Welding technology for highly active metals and high melting temperatures

 

In terms of welding properties, these metals (Zn, Hf, Nb, Ta, Mo, W) can be divided into two groups.

The basic measures to get solder joints with essential 
Highly active metals Zn, Hf, Nb, Ta: have good welding properties when adhering to welding conditions.

The elements have a high melting temperature Mo, W: more difficult to solder due to sensitivity to the impurities (crispy metal welding). In order to avoid cracking, Mo needs to heat the initial Mo 200 ÷ 315ºC and ram after welding to 980ºC for residual stress relief.
properties:

- Reduces harmful impurities in base metals and welding materials.

- Reduce the thermal stress and residual stress in welding joints.

- Protect metal welds and surrounding welds from outside air.

Methods of welding these metals

- welding with electron beam.

- Sold by non-melting electrode (reverse electrode) in the gas-containing chamber (using Ar, He has high purity).

- Mechanical weld metal reaches 80 ÷ 90% base metal.