3. The influence of electrode pressure on spot welding head. The electrode pressure has a significant impact on the total resistance R between the two electrodes. As the electrode pressure increases, R significantly decreases, while the increase in welding current is not significant and cannot affect the heat generation reduction caused by the decrease in R. Therefore, the strength of the solder joint always decreases with the increase of welding pressure. The solution is to increase the welding pressure while also increasing the welding current.

Molybdenum has extremely low Vapor pressure under the operating temperature and pressure of vacuum furnace. Therefore, molybdenum parts have relatively little pollution to furnace workpieces or working materials, and transpiration loss will not necessarily constrain the service life of molybdenum high quality parts such as heating elements and insulation packages.

The density of molybdenum is 10.2 grams per cubic centimeter, with a melting point of 2610 ℃ and a boiling point of 5560 ℃.