An introduction to vacuum furnace brazing technology -Part 3: some important criteria for vacuum brazing

摘要

It is very important to understand that the possession of a properly designed and installed vacuum furnace does not mean that first class brazing will result when the first jobs are processed in it. There are a number of supportive activities that need to be in place before this primary objective for installing the furnace can be expected. First and foremost there is a requirement for one or more persons on the staff to have a good understanding of what is needed in the way of maintenance in order to bring the equipment to the point where it will produce the required results, and having done so what actions have to be routinely taken to keep the furnace at that degree of excellence in performance. The typical criteria that need to be taken into account are the pressure rise-rate when in service, the frequency of the post-braze 'bake-out' operation, and specific pyrometry that on every occasion will include the uniformity of the furnace load as well as the uniformity of the charge space when the furnace is empty.