The quality of copper castings has a great influence on […]
The quality of copper castings has a great influence on the performance of mechanical products during operation. The wear resistance and dimensional stability of machine tool castings directly affect the accuracy of machine tools, and the impeller and casing of various pumps. The size of the inner cavity of the hydraulic component, the accuracy of the profile and the surface roughness directly affect the working efficiency of the pump and hydraulic system, the development of energy consumption and cavitation, etc., the cylinder block, cylinder head, cylinder liner, piston ring and exhaust of the internal combustion engine. The strength and resistance to chilling and heat of castings such as pipes directly affect the working life of the engine.
Copper castings are mainly used as blanks for machine parts, and some precision castings can also be used directly as parts of machines. Castings account for a large proportion of mechanical products. For example, in tractors, the weight of castings accounts for 50~70% of the weight of the whole machine, 40~70% of agricultural machinery, and 70~90% of machine tools and internal combustion engines. Among the castings, the most used castings are mechanical, the shape is the most complicated, and the amount is also larger, accounting for about 60% of the total casting output. Secondly, it is the steel ingot mold for metallurgy and the pipeline for engineering.
The special processing technology of copper castings has been developed, including: high-precision shaped copper strip, ultra-thin electrolytic copper foil, internal oxidized point strengthening, various metals, laser surface strengthening, semi-solid forming, profiled casting, particle-enhanced particle control, etc. .
High-precision shaped copper strip for copper castings
High-precision copper strip for transistor profiled frame, generally high-strength and high-conductivity alloy containing phosphorus and silver. The section consists of thick and thin sides, 1.27 mm thick side, 0.38 mm thin side, 68 mm bandwidth, and length greater than 200. Rice, production method, such as hole rolling, milling, high-speed forging, production of profiled section blanks, and then high-precision rolling, the key to the technology is high-precision rolling, the thickness of the thick side and the thin joint must be equal Otherwise, the shaped strip type can not meet the needs of users.
Oxidation-dispersion-enhanced oxygen-free copper in copper castings
The electric vacuum device requires oxygen-free copper. It does not deform during hydrogen gas welding at 930 °C. It is difficult to achieve the alloying method. Oxidation point dispersion strengthening method is commonly used at home and abroad. The common oxidation point AL2O3 is used.