Development of narrow band molybdenum for electric light source
Molybdenum is widely used in electric light source industry because of its small thermal expansion coefficient which can form gas seal connection with quartz or molybdenum group glass. For a long time, the broad molybdenum foil has been cut into narrow molybdenum about 100 mm in length and 2~4 mm in width in the lamp industry and then used as sealing material for special lamps after electrolysis. The disadvantages of this process are waste of material, unstable quality, low production efficiency, poor consistency of strip, short size of inner strip, and the introduced production line can not work continuously.
The research and development of narrow band of molybdenum has been carried out earlier in foreign countries, but there is no relevant data and no special national standard for this product. Through the test, we have solved the key technology in the production of narrow band molybdenum, worked out the processing technology, high yield, good quality. The successful development of this product has realized the localization of narrow band molybdenum production.
Molybdenum is a refractory metal, which is difficult to be processed and its processing technology is also complex.
The processing process of molybdenum foil is as follows: molybdenum plate failure → hot rolling → warm rolling → surface treatment → stress relief annealing → cold rolling → surface treatment → stress relief annealing → welding guide → cold rolling → finished product. Compared with the traditional wide molybdenum foil processing technology, the differences are as follows: (1) Molybdenum foil takes molybdenum slab as raw material, the process flow is long and the processing is complex. Molybdenum narrow strip is made of molybdenum wire and its processing technology is much simpler. (2) Continuous rolling is used for the narrow band of molybdenum, while intermittent rolling is only used for molybdenum foil.(3) Continuous elimination of molybdenum narrow band while the molybdenum foil needs to be fully stress-relieved annealing in a vacuum furnace or a hydrogen furnace.(4)The edges of molybdenum foil should be cut before the finished product, so it is allowed to have burr edges and cracks on the edges. Because the narrow strip of molybdenum is directly used after electrolysis, the edge is not allowed to appear such defects. (5)Compared with the blank of molybdenum foil, the narrow strip of molybdenum is easier to carry out surface cleaning. (6)Molybdenum foil to repeated rolling, due to deformation resistance, limited by the capacity of the equipment, the processing rate is small, and the narrow band of molybdenum due to small width, is not limited by the capacity of the equipment, as far as possible to use large processing rate, reduce processing.
