Difference between sandblasting and shot blasting for surface treatment of die castings

　　Surface treatment of aluminum alloy die castings by mesh belt shot blasting machine Shot blasting is efficient, but there will be dead corners, while sand blasting is more flexible, but the power consumption is large. Sand blasting uses high-pressure wind as power, while shot blasting is generally a high-speed rotating flywheel that ejects steel sand at high speed. The surface quality of the casting obtained by shot blasting is not as good as sand blasting, but it is more cost-effective than sand blasting. And it can remove some sticky sand that is difficult to clean from some castings, while sand blasting cannot. Sand blasting and shot peening are two different surface hardening processes. The hardness of sand blasting is lower than that of shot peening, and the tools used are also different! Sand blasting and shot peening are basically the difference between two spraying media, and of course the effects are also different: sand blasting is more delicate and easy to control accuracy and flatness; shot peening is more economical and practical, easy to control efficiency and cost, and the diameter of the steel shot can be controlled to control the spraying effect. QT37 hook shot blasting machine I. Characteristics of shot blasting

　　1. Metal or non-metal projectiles can be used arbitrarily to meet the different requirements of cleaning the workpiece surface;

　　2. The cleaning flexibility is large, and it is easy to clean the inner and outer surfaces of complex workpieces and the inner wall of pipe fittings, and it is not restricted by the site. The equipment can be placed near extra-large workpieces; 3. The equipment structure is relatively simple, the whole machine investment is small, there are few wearing parts, and the maintenance cost is low;

　　4. It must be equipped with a high-power air compressor station. Under the condition of the same cleaning effect, the energy consumption is relatively large; 5. The cleaning surface is prone to moisture and easy to rust again;

　　6. The cleaning efficiency is low, there are many operators, and the labor intensity is high.

　　Characteristics of shot blasting

　　1. High cleaning efficiency, low cost, few operators, easy to mechanize, suitable for mass production;

　　2. No compressed air is used to accelerate the projectile, so there is no need to set up a high-power air compressor station, and the surface to be cleaned is also free of moisture;

　　3. Poor flexibility, limited by the site, some blindness when cleaning the workpiece, and easy to produce dead corners on the surface of the workpiece that cannot be cleaned;

　　4. The equipment structure is relatively complex, with many vulnerable parts, especially parts such as blades that wear quickly, many maintenance hours, and high costs;

　　5. Generally, light and fine projectiles cannot be used. As we all know, in the processing of large steel castings, the surface treatment of steel castings is very important, which is related to the appearance quality of the finished steel castings. Usually, foundries use shot peening, shot blasting or sand blasting to clean the surface of steel castings.

　　Shot peening, the advantage of using shot peening for surface treatment is that the impact force is large and the cleaning effect is obvious. The disadvantage is that the treatment of thin plate workpieces by shot peening is easy to deform the workpiece, and the steel shot hits the surface of the workpiece to deform the metal substrate. Shot peening is a surface strengthening process widely used in factories. Its equipment is simple, low-cost, not limited by the shape and position of the workpiece, and easy to operate, but the working environment is poor. Shot peening is widely used to improve the mechanical strength, wear resistance, fatigue resistance and corrosion resistance of castings. It can also be used for surface matting, descaling and elimination of residual stress of castings. The difference from shot blasting is that shot peening uses high-pressure wind or compressed air as power, while shot blasting generally uses a high-speed rotating flywheel to eject steel sand at high speed. Shot peening is efficient, but there will be dead angles, while shot peening is more flexible, but the power consumption is large.

　　Although the two processes have different injection power and methods, they both aim to impact the workpiece at high speed, and their effects are basically the same. In comparison, shot peening is more delicate and easy to control precision, but the efficiency is not as high as shot peening. It is suitable for small workpieces with complex shapes. Shot peening is more economical and applicable, and it is easy to control efficiency and cost. The injection effect can be controlled by controlling the strength of the shot material, but there will be dead angles, which is suitable for batch processing of workpieces with a single shape.