1. Vacuum brazing characteristics
(1) During the whole brazing process, no flux is used, and the parts to be brazed are under vacuum conditions, so there will be no oxidation, carburization, decarburization, pollution and deterioration, and the brazing seam is beautifully formed.
(2) When brazing, the entire part is heated evenly and the thermal stress is small. The amount of deformation can be controlled to a minimum, and no margin processing and precision brazing can be achieved.
(3) Multiple adjacent brazing seams can be brazed at one time, or multiple components can be brazed in the same furnace according to the capacity of the furnace to improve brazing efficiency.
(4) There are many types of basic metals that can be brazed, especially suitable for brazing aluminum alloys, titanium alloys, stainless steel, high-temperature alloys, etc. It is also suitable for composite materials, ceramics, graphite, glass, diamond and other materials.
(5) The product design approach has been broadened, and components with narrow grooves, extremely small transition tables, blind holes, closed containers, and components with complex shapes can be used, without considering corrosion, cleaning, etc. caused by flux, etc. Destruction and other issues.
2. The main application of vacuum brazing:
Vacuum brazing technology has become a promising welding technology since its inception in the 1940s. At present, the vacuum brazing process has been promoted and popularized in aviation, aerospace, atomic energy, electrical instrumentation, petrochemicals, automobiles, tools and other fields. In terms of aero-engine applications, the JT9D engine honeycomb sealing ring of the Pratt & Whitney Company of the United States is made by vacuum brazing of rings and honeycomb sandwich cores; the engine fuel manifold and stainless steel heat exchanger are composed of vacuum brazing; JTBD engine 12 , 13-stage compressor stator ring is made of inner and outer rings and dozens of blades by vacuum brazing. The engine casing of GE in the United States is also made of more than 240 0.25-0.7~ thick Inconel alloy parts that are vacuum-brazed in three steps. Domestically, Shenyang Liming Engine Company and Chengdu Engine Company respectively apply vacuum brazing to aero-engines with some components. In recent years, with the development of science and technology, especially the high-speed development of the home appliance industry (especially the refrigeration industry, including refrigeration equipment, such as refrigerators, air conditioners and their three-way, four-way valves and other accessories), the automobile industry, and the electronics industry, The application of brazing technology is also becoming more and more extensive.
3. Main configuration of vacuum brazing equipment
· Working area size: 800mm (height) x 800mm (width) x 1500mm (length)
· Maximum temperature: 800℃
· Temperature uniformity: ±3℃
· Temperature control accuracy ≤±1℃
· Number of temperature control zones: 10 zones
· Working vacuum: 2×10-3Pa
· Furnace loading capacity: 1000kg
