With the increasing demand for weight reduction in aviation, aerospace, and military equipment, the demand for additive manufacturing of aluminum alloy parts is becoming more urgent. At present, the commonly used additive manufacturing aluminum alloy powder materials are AlSi10Mg, AlSi7Mg, etc., but the room temperature tensile strength after 3D printing is much lower than 400MPa, which cannot meet the high-performance requirements of aviation and aerospace equipment.
2319 aluminum alloy is an excellent high-strength aluminum alloy. The Chinese 3D metal printing material and equipment manufacturer NJZK uses self-developed arc additive manufacturing equipment with its deep process and equipment accumulation to overcome the large-scale arc printing of 2319 high-strength aluminum alloy. The key technology is the room temperature tensile strength of the forming material is 430MPa, the yield strength is 310MPa, and the elongation after fracture is 10%.
At present, the main additive manufacturing technologies that can realize the manufacture of aluminum alloy parts are: selective laser melting technology, electron beam fuse deposition technology and arc additive manufacturing technology. Among them, the selective laser melting technology is the most mainstream, but this technology has small forming dimensions and low manufacturing efficiency, and the aluminum alloy powder will undergo spheroidization and crystallization due to the reflection of the laser, resulting in poor surface forming quality and metallurgical bonding of the aluminum alloy. The electron beam fuse deposition technology has high efficiency and good quality, but the electron beam processing must be carried out in a vacuum environment. The uneven evaporation of metal components, expensive equipment, and the limitation of the structure size of the vacuum chamber are not conducive to the wide promotion of this technology. Arc additive manufacturing technology uses a lower-cost arc as the heat source; argon protection during welding (additive manufacturing) does not require expensive airtight chambers, and has less restriction on the size of parts; arc additive deposition efficiency is high, which can effectively reduce manufacturing Cost; At the same time, it avoids the high reflectivity of laser processing aluminum alloy and the uneven evaporation under electron beam vacuum. Therefore, the arc additive manufacturing technology has broad development prospects and application value in the field of aluminum alloy manufacturing.
In 2016, NJZK launched the WAAM1500 large-scale arc additive manufacturing equipment for the first time. The effective forming size of this equipment is 1500mm×1500mm×1000mm. It is equipped with advanced automatic control system and atmosphere control technology. It can print titanium alloy, aluminum alloy, stainless steel, copper alloy, low alloy steel and other materials; it can realize large-size parts High-efficiency and long-term stability forming processing.
Recently, NJZK used WAAM1500 arc additive manufacturing equipment to print and manufacture large aluminum alloy storage boxes with a diameter of about 2000mm, which strongly supported the development of national scientific research models. The large and complex hollow aluminum alloy structure adopts the traditional "equal material manufacturing" and "reduced material manufacturing" processes, with complex manufacturing processes, serious material waste and high manufacturing costs. The use of arc additive manufacturing technology can significantly simplify the manufacturing process, shorten the manufacturing cycle, and save manufacturing costs. At present, arc additive manufacturing has been applied to various fields such as metal bridges, large pressure vessels, engineering vehicles, petrochemical pipelines, missile launchers, landing gears, and tank armor, and has broad application prospects.