Powder metallurgy vs casting

Powder metallurgy vs die casting

1. Raw materials

Casting – Casting materials are usually non-ferrous materials, such as aluminum, magnesium, zinc, which have low melting points. The shape of the casting product can be plate, belt, rod, etc.;

Powder metallurgy – Metal or metal powder (or a mixture of metal powder and non-metal powder) as raw materials. Although there are standard powder metal materials, it is also possible to mix powders. This allows the creation of specific properties, such as the high magnetic properties of motor components, that require high melting point metal powders. Powder metallurgy usually consists of the following materials: stainless steel, iron, nickel, titanium, copper, silicon, phosphorus.


2. Process

Casting – is the use of material from liquid to solid phase transition molding, the metal is completely melted, the final product structure changes.

Powder Metallurgy – is the process technology of making metal or metal powder (or a mixture of metal powder and non-metal powder) as raw materials, forming and sintering, manufacturing metal materials, composites and various types of products.


3. Heat treatment

Casting – According to different materials and performance requirements can have different heat treatment processes, such as aluminum alloy annealing, quenching, solution treatment, aging strengthening;

Powder metallurgy – conventional powder metallurgy method, the material can not be completely dense, inevitably produce some gaps, will reduce its strength, according to the different requirements of material properties, determine whether the heat treatment after sintering, generally through quenching and tempering can improve the performance of the material.


 4. Organization control

Casting – In die casting, the control of the microstructure is determined by the cooling rate, which depends on factors such as surface area and volume, and the casting organization is generally more dense.

Powder metallurgy – Powder because the raw material is relatively small, through process control, can obtain uniform grain, fine microstructure, completely avoid the composition and microstructure segregation generated by casting. Each cycle deposits a uniform weight of powder into the mold and compacts it to the same density. Powder metallurgy materials are hot isostatic pressing, and the density of ordinary sintered materials is not as good as casting.


5. Mechanical properties

Compared with some other processes, die casting offers very good molding capabilities. However, we can use almost the same design possibilities as powder metallurgy products to give products better mechanical properties.

Die cast materials are not magnetic. Unless they are set inside another component made of another metal, there is no magnetic suitability. Powder metallurgy has a variety of magnetic materials available. Another problem with die casting is that the product is fragile and easily broken. The main materials of the die-cast parts are zinc and aluminum, which are relatively soft metal materials. Powder metallurgy parts, usually made of steel, have higher hardness. Using stronger materials can achieve the same shape with less material, which can save motor design space and weight.


6. Cost

Component design is the main driver of cost, although the design can be customized to suit the molding process. However, there are differences between powder metallurgy products and die casting, and these differences are also the main factors affecting the cost.

Material use/yield. Powder metallurgy products have a lower scrap rate, which is a huge advantage in the use of high-value materials such as copper and stainless steel.

Secondary processing. Die cast parts need to be trimmed to remove raw edges, remachined and heat treated; Most powder metallurgy parts do not require secondary processing.

Raw material consumption. Melting metals is energy intensive, especially for materials with higher melting points. Although sintering is also energy intensive, the total consumption of sintering may be less than that of casting.

Post time: Aug-23-2023