Industry Characteristics of Precision Casting

Among them, Investment Casting is more commonly used in investment casting, also known as lost wax casting: use suitable investment materials (such as paraffin) to make investment molds; repeat the process of dipping refractory paint and spreading refractory sand on the investment mold to harden the shell and Dry; then melt the internal investment to obtain a cavity; bake the shell to obtain sufficient strength, and burn off the residual investment material; pour the required metal material; solidify and cool, and remove the sand after shelling, Thereby a high-precision finished product is obtained. Heat or cold work and surface treatment as required by the product. For example, in sand casting, mass-produced factories should create conditions to adopt technologically advanced modeling and core-making methods. The old-fashioned shock-type or shock-pressure molding machine production line is not high enough in productivity, labor-intensive and noisy, and cannot meet the requirements of mass production, so it should be gradually transformed. For small castings, a boxless high-pressure molding machine production line with horizontal or vertical parting can be used, which has high production efficiency and small footprint for solid molding; for medium parts, various boxed high-pressure molding machine production lines, gas Punching molding line, in order to meet the requirements of fast and high-precision molding production line, core making methods can be selected: cold core box, hot core box, shell core and other efficient core making methods.

For medium-volume large castings, the application of resin no-bake sand can be considered for molding and core making.

For heavy castings produced in small batches, manual modeling is still an important method. Manual modeling can adapt to various complex requirements and is more flexible, and does not require a lot of process equipment. It can be applied to water glass sand mold, VRH water glass sand mold, organic ester water glass no-bake sand mold, clay dry mold, resin self-hardening sand mold and cement sand mold, etc. For heavy castings produced in a single piece, the pit molding method is low in cost and can be put into production. quick. For mass-produced or long-term shaped products, it is more appropriate to use multi-box molding and split-box molding methods. Although the initial investment in molds and sand boxes is high, it can be compensated by saving molding time and improving product quality.

Casting methods such as low pressure casting, die casting and centrifugal casting are only suitable for mass production due to the expensive equipment and molds.

Conditional method should be suitable

For example, in the production of castings such as the bed of large machine tools, the core forming method is generally used, instead of making patterns and sand boxes, cores are formed in the pit; while other factories use the sand box modeling method to make patterns. Different enterprises have different production conditions (including equipment, site, staff quality, etc.), production habits, and accumulated experience. According to these conditions, we should consider what products are suitable and what products are not suitable (or cannot).

Accuracy Requirements and Costs

The accuracy of castings obtained by various casting methods is different, the initial investment and productivity are also inconsistent, and the economic benefits are also different. Therefore, in order to achieve more, faster, better and more economical, all aspects should be taken into account. A preliminary cost estimate should be made for the casting method selected to determine the casting method that is cost-effective and can meet the requirements of the casting.

Although the development of my country's foundry industry is in a relatively difficult period, from a long-term perspective, there is still some hope for the development of my country's precision casting industry. The market demand has slowly started to pick up, and my country's foundry industry has It is believed that my country's foundry industry will definitely achieve gratifying results.

Experts said that in order to fundamentally improve the level of casting technology, the following four points must be achieved:

First, develop simulation technology, improve the accuracy of prediction, strengthen process control, and improve yield. The problem of regularity is not well grasped, which affects the yield in mass production.

Second, the combination of production, education and research. In addition to the enhancement of innovation awareness and the improvement of research and development capabilities, the independent innovation of enterprises also needs to pay attention to and strengthen the combination of "production, learning and research" with precision casting enterprises as the main body.

Third, attach importance to material research and development. Materials are the foundation of industry, and there is still a lot of work to be done. In the field of aerospace, the research and smelting technology of alloy materials, especially some new materials such as high-temperature alloys, still needs to be improved, and there is still a big gap with foreign countries.

Fourth, pay attention to the improvement of equipment technology. The process is mainly a problem of equipment. Many key equipment, such as some directional solidification equipment, mainly rely on imports. Therefore, the research and development of precision casting equipment is still the focus.