History of investment casting
Investment casting is an ancient and sophisticated casting process that dates back to around 4000 BC. The following is an overview of the historical development of investment casting:
1. Ancient investment casting: The earliest investment casting technology can be traced back to ancient Mesopotamian civilization and ancient Egyptian civilization. The ancient Egyptians used plaster molds for investment casting to make gold and silver jewelry and ornaments. Similar investment casting techniques were used in ancient India and China to make artifacts such as bronzes and bronze ware.
2. Medieval investment casting: Medieval Europe was the period when investment casting technology was developed and promoted. In the Middle Ages, investment casting technology was widely used to make works of art such as large bells, church decorations, and sculptures. The development of investment casting technology provided important support for medieval art and architectural styles.
3. Industrial Revolution period: With the arrival of the Industrial Revolution, investment casting technology has been further developed and applied. At the end of the 19th century and the beginning of the 20th century, investment casting technology was widely used in the manufacture of auto parts, aircraft engine parts, ship parts and other industrial products. The precision and complexity of investment casting technology continue to improve, bringing great convenience and benefits to industrial production.
4. Modern investment casting: With the continuous progress of science and technology and the development of material engineering, modern investment casting technology has become a high-precision and high-efficiency casting process. Modern investment casting technology combines CAD/CAM technology, CNC machining technology and material engineering technology, which can realize the precision casting of complex parts and meet the needs of various industrial fields.
The importance of investment casting
Investment casting is an important casting process that has the following importance:
1. Manufacture complex parts: investment casting technology can produce parts with complex shapes and precise structures, including parts with complex internal structures and uneven wall thickness that are difficult to achieve with other casting methods. This makes investment casting become one of the important processes for manufacturing high-precision and high-demand products such as aircraft engine parts, auto parts, and construction machinery parts.
2. Improve production efficiency: investment casting technology has the characteristics of high automation and high production efficiency, which can produce the same or similar parts in large quantities, improve production efficiency and reduce production costs. This makes investment casting become one of the important casting processes in industrial production.
3. Save material resources: investment casting technology can effectively use metal materials, reduce waste and improve material utilization. At the same time, investment casting can also realize the recycling of resources and reduce environmental pollution by recycling waste and used parts.
4. Improve product quality: investment casting technology can achieve precision casting of parts, ensure the dimensional accuracy and surface quality of products, and improve the quality and performance of products. The advantages of seamless structure, no porosity inside and smooth surface can be achieved through investment casting to ensure that products meet high quality requirements.
5. Promote industrial development: The development and application of investment casting technology has promoted the development of industry and provided important technical support for aerospace, automobile manufacturing, energy equipment, construction machinery and other fields. The continuous improvement and innovation of investment casting technology will further promote the modernization and intelligent development of industry.
What is the process of investment casting
Investment casting is a precision casting process whose process usually consists of the following main steps:
1. Mold making: First of all, make investment mold according to the design requirements of the product. Investment molds are usually made of high temperature resistant materials, such as silica gel, gypsum, ceramic, etc. The structure, size and surface quality requirements of the product need to be considered in the mold making process.
2. Mold drying: The investment mold needs to be dried to remove the water in the mold and ensure that the mold will not produce bubbles or cracks during the casting process.
3. Investment casting: Put the investment mold into the grouting machine, and inject the wax liquid or other solution in the investment mold through vacuum suction to form the wax mold. The wax mold needs to be coated and dried several times to ensure the thickness and surface smoothness of the wax mold.
4. Dewaxing: the wax mold after grouting is heated in the dewaxing furnace, so that the wax mold is completely melted and flowed out, leaving a cavity to form an investment mold.
5. Melting metal: The required metal material is heated to a molten state, usually using an electric furnace or other melting equipment for melting.
6. Pouring: Pour the molten metal into the investment mold and fill the entire cavity. The temperature and flow rate of the metal need to be controlled during the pouring process to ensure that the filling is complete and no bubbles are generated.
7. Cooling and curing: After the metal is fully filled with the investment mold, wait for the metal to cool and solidify to form the casting.
8. Mold crushing: After the casting is completely cooled, the investment mold is broken or chemically dissolved, and the casting is removed.
9. Post-treatment: grinding, cleaning, heat treatment and other post-treatment processes for castings to achieve the product's surface smoothness and dimensional accuracy requirements.