With the continuous development of enterprises, new customers have joined in succession, the diversification of old customers'products and the increase of orders, this urgently requires us to expand the production scale, and the existing factory buildings of more than 8000 square meters can no longer meet the production needs. In 2018, the company absorbed and merged Wuxi Tias Commercial and Trade Co., Ltd. and added 6448 square meters of land. Construction began in May this year for the renovation and expansion of the plant. After completion, part of the plan will be used to expand existing production lines, including injection molding, assembly and finishing, and part will be used to develop new business areas.

The improvement of casting quality requirements will lead to the reduction of machining allowance and defects. Therefore, some precision heat-resistant steel castings deflectively cast in air or vacuum, previously considered qualified, are now judged as scraps. Typical examples of this situation are surface defects of heat-resistant and corrosion-resistant steel castings, a previously acceptable defect known as "corrosion".

In actual production, it is often necessary to analyze casting defects in order to find out the causes of defects, so as to take measures to prevent them. For the designer of precision casting, it is helpful to know the defect of product and its causes, to design the casting structure correctly, and to draw up the technical requirements appropriately according to the actual conditions of casting production.
There are many defects in precision casting. The causes of defects are very complex. Sometimes it can be seen that there are many defects caused by different reasons on the same casting, or that the same reason may cause many defects when the production conditions are different.

Whether the defective precision castings are regarded as scrap or not must be determined according to the use and requirement of the castings and the location and severity of the defects. Generally, if there are minor defects, it can be used directly; if there are medium defects, it can be used after repair; if there are serious defects, it can only be scrapped.

The level of precision casting is the standard to decide whether a country's foundry industry is strong or not. Therefore, if China's foundry industry wants to make a brilliant turn, it must give priority to the development of precision casting if it wants to become a powerful foundry country.

In recent years, China's precision casting production has made great progress, and China has become a big country in precision casting manufacturing. The rapid growth of China's industrial level in a wide range is closely related to the development of foundry industry. Foundry is the foundation of all industries. Without the support of foundry industry, the dream of entering tens of millions of families of automobiles in China is almost impossible to realize. A country's industry can not be revitalized without advanced manufacturing technology, and casting should undoubtedly rank first in the advanced manufacturing technology. Therefore, the level of foundry technology has become an important symbol to measure the level of a country's manufacturing industry, and is also the key to the level of a country's industrial development.

It is an indisputable fact that China is a foundry power rather than a foundry power. At present, China's foundry industry is moving towards a new stage of foundry power. In order to promote the jump development of foundry industry, the key is to develop precision casting.

Precision casting is one of the foundry industries in the world. Some people in the world divide a country's foundry level according to the development status of precision casting technology. Therefore, precision casting is also the representative of the development status of foundry productivity. In order to promote the development of China's precision casting industry, it should advance to the following four goals.

In addition to the large number of factories, employees and output, there are gaps in quality, efficiency, energy and material consumption, labor conditions and environmental protection between China and developed countries. It is reported that the development of precision casting technology in the developed industrial countries in the world has four goals, which should be approached by the investment casting industry in China.

1. Improve the quality and reliability of castings and produce high quality near-net shape castings.
2. Shortening the delivery time;
3. Protecting the environment, reducing or even eliminating pollution;
4. Reduce production costs.

At present, China's precision casting industry can not achieve these goals. In order to make China's precision casting industry reach the advanced level in the world, we must proceed from China's reality and promote the development of precision casting industry as soon as possible.

Improving the quality and yield of castings, shortening the delivery time, saving energy and reducing emissions, and reducing costs are not only the direction of our compact casting industry, but also the common goal of the world precision casting industry. Whoever achieves the goal first can seize the industry's commanding heights. China's precision casting should rapidly advance to the four goals.

Casting refers to the process of pouring solidified material into a specific shape of casting mould at room temperature for solidification and forming. Most of the cast materials are solid but heated to liquid metal (e.g. copper, iron, aluminium, tin, lead, etc.), while the casting materials can be sand, metal or even ceramics. According to different requirements, different methods will be used. The products produced in this way are called castings. Metal mould can cast nodular iron and gray iron.

Advantage:
It can produce parts with complex shape, especially the blank with complex inner cavity (such as heating) 2, which has wide adaptability and can be cast by metal materials commonly used in industry. A few grams to hundreds of tons. 3. Raw materials come from a wide range of sources. The price is low. The shape and size of scrap, scrap and chip 4 castings are very close to the parts, reducing the amount of cutting, which belongs to less or no cutting. Because of the good heat dissipation conditions in the metal mold, the fluidity of the liquid metal must be poor, in addition, the stress is also large, and the thin wall is prone to white mouth. Metal mould can cast nodular iron and gray iron.

Disadvantages:
Mechanical properties are not as good as forgings (coarse structure, many defects, etc.) 2. In sand casting, single piece, small batches, workers'labor intensity is high. 3. Casting quality is unstable, there are many processes, and the influencing factors are complex. It is easy to produce many defects.

Application:
Widely used: agricultural machinery 40-70% machine tools: 70-80% weight castings.