The similarities and differences of powder metallurgy and casting process

Powder metallurgy is a science and technology that studies and manufactures various metal powders and uses the powders as raw materials to prepare metal materials and products by pressing, sintering and necessary subsequent processing. It is a mass production method with little or no cutting, which can make structural parts with complex shapes and high structural strength while reducing costs. It is the main method for mass production of bearing self-lubricating parts at low cost.
Advantages of powder metallurgy process
Advantages: 1. Most refractory metals and their compounds, oxide dispersion strengthened alloys, porous materials, ceramic materials and cemented carbides can only be manufactured by powder metallurgy methods.

2. Since the powder metallurgy method can be pressed into the final size of the blank without or little need for subsequent mechanical processing, it can greatly save the amount of metal and reduce the cost of the product. When manufacturing products by powder metallurgy, the loss of metal is only 1-5%. When produced by ordinary casting methods, the loss of metal may reach 80%.

3. Since the powder metallurgy process does not melt the material in the material production process, it is not afraid of mixing impurities, and the sintering is carried out in a vacuum and reducing atmosphere, not afraid of oxidation, and will not cause any pollution to the material, so it is possible to obtain high purity. s material.

4. Powder metallurgy can ensure the correctness and uniformity of material composition ratio.

5. Powder metallurgy is suitable for producing products with the same shape and a large number of products, especially gears and other high-cost products. Manufacturing by powder metallurgy can greatly reduce production costs.
Disadvantages of powder metallurgy process
1. Consider the size of the part when there is no batch size
2. The mold fee is higher than the casting mold

Development direction of powder metallurgy materials and products
1. The representative iron-based alloys will be developed into large-volume precision products and high-quality structural parts.
2. Manufacture of high-performance alloys with uniform microstructure, difficult to process and completely dense.
3. Use the enhanced densification process to manufacture special alloys of general oil-containing mixed phases.
4. Manufacture of heterogeneous materials, amorphous, microcrystalline or metastable alloys.
5. Machining of unique and unusual forms or compositions of alloy parts.

Casting is a process in which metal is smelted into a liquid that meets certain requirements and poured into a mold. After cooling, solidification, and cleaning, a casting with a predetermined shape, size and performance is obtained.

Casting Features:
1. Casting has a wide source of raw materials and low production costs. Compared with other forming processes, casting has obvious advantages.
2. Casting is liquid metal forming, so it can produce blanks or parts with complex shapes, especially various sizes and specifications with complex inner cavities.
3. The size, weight and production batch of castings are not limited, which is more flexible
4. Low production cost and resource saving. The utilization rate of materials is high and the application is very wide
5. The mechanical properties of castings are worse than forgings
6. Due to the large number of casting production processes, many materials, and poor control, the quality of the castings is unstable, and the scrapped products are relatively high.
7. Poor working conditions
Casting advantages:
1. Produce complex shapes, especially blank parts with complex inner cavities, such as various boxes, beds, racks, etc.
2. Castings have wide adaptability and flexibility. Commonly used metal materials in the industry can be used for casting. The weight of castings can range from a few grams to several hundred tons, and the wall thickness is about 0.5mm to 1m.
3. The raw materials of castings are cheap and low in cost
1. The structure of the parts is loose, the grains are coarse, and defects such as shrinkage cavities, shrinkage porosity, and pores are easily generated inside. Therefore, the mechanical properties of the castings, especially the impact toughness, are lower than those of the forgings of the same material.
2. The casting quality is not stable enough.

Post time: Mar-31-2022