Brass casting is a kind of brass molding object Bai obtained by various casting methods, that is, the melted liquid metal is injected into the prepared casting mold by pouring, injection, inhalation or other casting methods, and then cooled, sand falling, cleaning and post-treatment are carried out to obtain the object with certain shape, size and performance.
Brass casting has a long history of application. In ancient times, people used castings to make coins, sacrificial vessels, weapons, tools and some living utensils. In modern times, brass casting is mainly used as blank of machine parts, and some precision castings can also be directly used as machine parts. Brass casting occupies a large proportion in mechanical products. For example, in tractors, the weight of brass castings accounts for 50-70% of the whole machine weight, 40-70% in agricultural machinery, and 70-90% in machine tools and internal combustion engines.
Among all kinds of castings, mechanical casting has the most varieties, the most complex shape and the largest consumption, accounting for about 60% of the total brass investment casting output. The second is ingot mould for metallurgy and pipeline for engineering.
Brass casting is also closely related to daily life. For example, frequently used doorknobs, door locks, radiators, water pipes, iron pans, gas stoves, irons, etc., are all castings.
After a series of processing, such as grinding, finishing, polishing and so on, the brass casting works must be surface treated to present the author’s design intention and the appearance color in accordance with the connotation of the work in order to obtain the ideal artistic effect
Due to the influence of many factors, brass castings often have some defects, such as blowhole, pinhole, slag inclusion, crack, pit and so on.
The commonly used repair equipment for brass castings are argon arc welding machine, resistance welding machine, cold welding machine, etc. The defects of brass castings with low quality and appearance can be repaired by argon arc welding machine with high heat and high speed. However, in the field of precision lost wax brass casting defect repair, due to the great influence of argon welding heat, the casting deformation, hardness reduction, sand hole, local annealing, cracking, pinhole, wear, scratch, undercut, or insufficient adhesion and internal stress damage will be caused. The cold welding machine overcomes the above shortcomings, and its advantages mainly lie in the small heat affected area, no preheating of brass castings, cold welding repair at room temperature, no deformation, undercut and residual stress, no local annealing and no change of the metal structure state of the casting.