Possible scrapping of vacuum brazing furnace products and Solutions – 2

6、 Product hidden damage scrapping
7、 Scrapping of tooling fixture
8、 The perpendicularity of the product can not meet the requirements of the drawing and be scrapped
9、 Scrapping of bonding die products
10、 Scrapping of projectile (product displacement)

6、 Product hidden damage scrapping
1. Phenomenon and reason: in the process of product clamping, the ceramic plate used on the bottom plate, due to poor quality, after clamping, after pressing, the high-temperature brazing ceramic forms few blocks. In the process of oiling on the plate or film. Caused by product stacking operation.
2. Solution: use high-quality solder resist, or use 99% ceramic chip or modify process flow without ceramic chip.

7、 Scraping of product
1. Phenomenon and reason: refers to the clamping ring loose in the brazing process and touches the product sheet or flange, resulting in product scrapping, which is called scraping.
2. Solution: the claws should be relative to each other when entering the furnace, or can be separated by small iron bars or tied with iron wire. In addition, the position and method of clamping ring should be considered in the design requirements;

8、 The perpendicularity of the product can not meet the requirements of the drawing and be scrapped
1. Phenomenon and reason: in the high temperature brazing, the product inclines in all directions, resulting in the scrapping of the product verticality. Main reasons for scrapping:
(1) The furnace support was broken, so that eight girders were not horizontal.
(2) The furnace bars and bars are not straight when they are put into the furnace.
(3) The pillars on the furnace railing are uneven due to the deformation of stainless steel.
(4) The thickness of welding die is not uniform, so it should be carefully selected when entering the furnace.
(5) The verticality of the matching table does not meet the requirements during product assembly. Repair the assembly stand.
2. Solution: according to different products, contact me at 13905275926 to discuss and solve the problem step by step.

9、 Scrapping of bonding die products
1. Phenomenon and reason: when the brazing process is high temperature, the copper flux overflows and sticks to the welding mold, which makes the product scrapped.
2. Solution: there are three main reasons for the formation of bonding die
(1) The high temperature period of vacuum brazing process is too long and the temperature is too high. The partial pressure of nitrogen in the furnace can not meet the requirements, and the partial pressure requirement is 2.0e2.
(2) The aluminum oxide powder is not painted well or the position of ceramic plate is not correct.
(3) Too much copper solder

10、 Scrap of pellet
1. Phenomenon and reason: it refers to that a certain section of the upper core piece and the lower core piece cannot be combined together in the process of brazing. Or if the film is seriously ejected and scrapped, it is called the scrap of the cartridge.
2. Solution: for 403 material, the effective way is to place the bottom plate upward, that is, the welding seam is upward. The heating process should not be intermittent. If the above brazing method can not be resolved, the structural design must be corrected.