What are the advantages and disadvantages of powder metallurgy products and casting

What are the advantages and disadvantages of powder metallurgy products and casting

What are the advantages and disadvantages of powder metallurgy products and casting? Here is the introduction of Zhang Wei's editor:

1、 Comparison of advantages of powder metallurgy products

When comparing powder metallurgy products with casting, it is important to look at the following factors: quality, significant impact, mechanical properties, cost, and application.

Both powder metallurgy products and die-casting need to be filled with molds to form the required shape. Then the formed parts are released - this process will affect the design of parts and tools. This is where the similarity ends. In die casting, molten metal is poured into the mold where it solidifies. After demoulding, it usually goes through multiple mechanical processing and heat treatment. In contrast, the powder metal process involves the use of cold powder. When the mold is full, the upper tool is lowered to compact the powder. Then the mold opens and the part is ejected. Many powder metal parts are then sintered to fuse the mixture into a hardened part.

2、 The place where powder metallurgy products and die casting are separated

Although these processes have similarities, many advantages and disadvantages of powder metallurgy products are quite different from those of casting.

3、 Quality

In die casting, turbulent liquid fills the cavity. Sometimes this can trap air, resulting in unfilled (your material does not fill the mold). The oxide skin will fall into the liquid and cause internal defects. Streamlines and pores are common. In order to verify the integrity and detect defective parts after casting, sometimes you need: leak test, x-ray, other inspection. One of the advantages of powder metallurgy products is consistency. Each cycle will deposit a uniform weight of powder into the mold and compact it to the same density. Internal defects are highly unlikely if powder metal manufacturers follow good housekeeping practices and avoid powder contamination. The advantage is to control the microstructure. In die casting, this is determined by the cooling rate, which depends on such factors as surface area and volume. Powder metallurgy products can better control porosity and consistency, and can form more fine microstructure.

4、 Significant impact

Die casting is often used for non-ferrous materials, such as aluminum, magnesium and zinc, mainly because of the low melting point of these metals. Powder metallurgy products have greater flexibility in material use and alloy selection. In particular, although there are "standard" powder metal materials, mixed powder is also feasible. This allows the creation of specific characteristics - such as high magnetic properties of motor components - and high melting point metal powders. Powder metal usually consists of one of the following materials: stainless steel, iron, nickel, titanium, copper, silicon, phosphorus

5、 Mechanical properties

Compared with other processes, die-casting provides a good molding ability. However, you can take advantage of almost the same design possibilities as powder metallurgy products, but with better mechanical properties. However, powder metals have a variety of magnetic materials available. Another problem of die castings is that they are fragile and easily broken. The main materials of die-casting parts - zinc and aluminum - are relatively soft metals, which is of no use. Powder metal parts, usually made of some form of steel, can withstand more abuse. Using stronger materials can achieve the same shape with fewer materials, which can save space and weight in motor design.

6、 Cost

Component design is the main driver of cost, although the design can be customized to adapt to the molding process. However, there are differences between die-casting and powder metallurgy products, which have significant cost impact. Material use/output. The scrap rate of powder metallurgy products is low, which has great advantages in secondary processing when using high value materials such as copper and stainless steel. Die casting parts almost always need to be trimmed to remove burrs, plus some machining operations and possible heat treatment. Most powder metal parts hardly need secondary processing. Energy consumption. Molten metal is energy-intensive, especially for materials with high melting point. Although sintering is also energy-intensive, the total consumption of sintering may be less than that of casting.

7、 Application

Many of us have played matchbox cars in our growth. This is an example of die casting. The metal shell of the car is a complex shape, which is very suitable for this process. Over the years, other more important uses of die-casting include: signs on cars, die-casting of train wheels, and rods in two-stroke engines.

8、 Consider two processes

Powder metallurgy products and die casting are near-net forming processes. However, in many cases, powder metallurgy products have obvious advantages over casting. When processing materials with high value and high melting point, the advantages of powder metallurgy product technology are particularly obvious. Remember, this metalworking process provides greater flexibility in the use of materials - thus expanding your design possibilities for automotive parts and several other applications.

I hope this article can help you.