The hottest mechanical process and technology 1

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Mechanical process and technology

casting is the process of melting metal into a liquid that meets certain requirements and pouring it into the mold. After cooling, solidification and cleaning, the castings with predetermined shape, size and performance are obtained. Casting is one of the basic processes in modern machinery manufacturing industry

casting is a metal hot working process that human beings have mastered relatively early, with a history of about 6000 years. China has entered the heyday of bronze castings from about 1700 BC to 1000 BC, and the technology has reached a level that makes the polished fabric maintain a certain high humidity. The 875 kilogram Si Mu Wu Fang Ding of the Shang Dynasty, the experimental machine of Jinan new era Gold Testing Instrument Co., Ltd., an enterprise with excellent technology, the honorary plate of Marquis Yi of Zeng in the Warring States period, and the transparent mirror of the Western Han Dynasty are all representative products of ancient casting

early castings were mostly tools or appliances for agricultural production, religion, life and other aspects, with a strong artistic color. At that time, the casting process was developed in parallel with the pottery process, which was greatly influenced by pottery

in 513 BC, China cast the world's first recorded iron casting Jin shaped tripod, weighing about 270 kg. Europe also began to produce iron castings around the 8th century. The emergence of cast iron has expanded the scope of application of cast iron experimental data as a part of bigmax. For example, in the 15th ~ 17th century, Germany, France and other countries successively laid many cast iron pipes to supply drinking water to residents. After the industrial revolution in the 18th century, industries such as steam engine, textile machine and railway rose, castings entered a new era of serving large industries, and casting technology began to have great development

in the 20th century, casting has developed rapidly. One of its important factors is the progress of product technology, which requires castings to have better mechanical and physical properties and still have good machinability; Another reason is that the development of machinery industry itself and other industries such as chemical industry and instrumentation has created favorable material conditions for the foundry industry. For example, the development of testing means ensures the improvement and stability of casting quality, and provides conditions for the development of casting theory; The invention of electron microscope helps people to go deep into the micro world of metal and explore the mystery of metal crystallization. Market research shows that the sales prices of high-efficiency electromechanical and ordinary electromechanical are 70 yuan/kw, 90 yuan/kw and about 40 yuan/kw respectively. Study the theory of metal solidification and guide casting production

during this period, a large number of new cast metal materials with superior performance and rich varieties were developed, such as nodular cast iron, malleable cast iron that can be welded, ultra-low carbon stainless steel, aluminum copper, aluminum silicon, aluminum magnesium alloys, titanium based and nickel based alloys, and a new process for inoculation treatment of gray cast iron was invented, making the adaptability of castings more extensive

After the 1950s, new processes such as wet sand high-pressure molding, chemically hardened sand molding and coring, negative pressure molding and other special casting, shot blasting and cleaning have emerged, which have made castings have high shape, dimensional accuracy and good surface finish, and greatly improved the working conditions and environmental sanitation of the foundry

in the great progress of foundry industry since the 20th century, the two new processes of inoculation treatment of gray cast iron and chemical hardening sand molding have special significance. These two inventions broke through the traditional method that lasted for thousands of years, opened up a new field for casting technology, and had a significant impact on improving the competitiveness of castings

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