This process is consisted of 4 main stages:
1. Powder Preparation: The most common method is to spray the molten material (atomizing). Molten metal streams from a canal and atomized in the course of the spray of a gas or liquid. Produced powder is collected and sorted before use.
2. Mixing: Pure Powder is rarely comprises the entire favorite properties; thus it is a normal remedy to mix them with types of powders.
3. Compress: Powder, in this stage, is condensed and compacted to desired shape. Acquiring a high and consistent density is a preferred property which is achievable with a versatile compression. For this purpose especial Press molds are used with jacks to implement the force from two directions. Hydraulic, Mechanical or a combination is used in this method. Imposed pressure is some 10-30 ton/inch2, however, today press machines provide a pressure up to 300 ton/inch2. Operating dies should be made of high hardness tool steels to confront Abrasive behavior of grains. To press more abrasive powders, or in mass Productions molds are made of Cemented Carbides.
4. Sintering: Compacted work piece is cooked with a high temperature in a controlled atmosphere, in Sintering stage. Most of Metals can be sintered in a 70% to 80% of their melting point. In cases the product is mixed of two or more substances, Sintering temperature may be higher than melting points of some components, which melt and breaches in fissures of sintered materials. Very high temperatures result in oxidation before metal grains fusion. Reductant atmospheres, the most common of which are atmospheres with a base of Hydrogen, derived from a broken molecule of Ammoniac or broken Hydro-carbons; which not only reduces –almost- every kind of oxide deposited on particles, but burns harmful derived gases meanwhile sintering, are preferred to other sintering atmospheres.
Some secondary operations like Sizing, Saturation and feeding are carried out to achieve especial properties or more accuracy.
Advantages of PM process:
1. None or less need for machining.
2. More production capacity/rate
3. High Variety of raw material
4. The vast range of acquired properties
5. Producing complicated features
6. None or less scraps
Tabriz Powder Metallurgy Co. continues the activity with current capacity of 400 tons of annual products using Powder Metallurgy methods. Iron pieces mostly used in home appliance factories, vehicle industries, agriculture machinery, etc. have the larger share of products. More ever, this company has the capability of production of PM fabricated Bronze parts. Email us to find more details on Tabriz Powder Metallurgy Co. products.
PM Products can be classified in 5 general categories, as below:
1. Porous pieces with controlled porosity, e.g. filters.
2. Complicated features that call for several and numerous machining operations.
3. Products with difficult machining or high hardness.
4. Products that are required to show properties of many substances as for circumstances.
5. Products, to which PM can give better mechanical properties.