Basics of Powder Metallurgy

Powder Metallurgy-Present and Future Scope: Production of components by taking initial methods in the form of powder is called as Powder Metallurgy. In this article, we will learn about the Present and Future Scope of Powder Metallurgy with its advantages and disadvantages in a detailed way.

CONTENTS of Powder Metallurgy:

• Introduction to Powder Metallurgy(PM)
• What makes the Powder Metallurgy exist?
• Powder Metallurgy Processes

1. Production of Powders
2. Mixing/Blending
3. Compaction
4. Sintering

• Advantages & Dis-Advantages
• Markets for Powder Metallurgy components
• Present and Future Scope
• Applications of Powder Metallurgy

A form of Powder Metallurgy existed in Egypt as early as 3000 B.C Used in 19thcentuary to produce Platinum and Tungsten wires. Utilized in Germany for producing Tungsten carbide cutting tools after 1stWorld war.

Definition:

Production of components by using initial methods in the form of powders is known as powder metallurgy. Failure of General alloy formation makes the powder metallurgy to exist.

POWDER METALLURGY Processes:

1.Production of Powders:

• Molten liquid is pressurized(P) and allowed to travel through a nozzle of diameter (Dn).
• The molten liquid will break into spherical droplets and are cooled in quench medium.
• They will be solidified and powder of particle size(Dp) is produced.

3.Compaction:

• Wet condition of powder mixture will be kept in the mould and is subjected to compression load under pressure.
• After compaction, the wet condition of powder mixture is called compact.
• The compact possesses low strength compared to the final strength of component called Green Strength.

4. Sintering

• The compact is heated to 80% of M.P. temperature.
• Due to this chemical bonds will form among atoms and thereby, strength increases.
• Sintering is performed in inert atm.(N2/Ar) or in the presence of vacuum to avoid oxidation.
• After sintering, the compact will achieve tremendous strength called as final strength.

Advantages of Powder Metallurgy:

• Alloys can be created from high MP metals including MO, W, Tantalum.
• Used for metals that are too hard to machine.
• In Super hard cutting tool bits, the tips will be coated with Fe3C, WC, SIC coatings by PMP.
• In the production of Ceramics (sustain a temp. of 3000’c), PMP will be used.
• Powder metallurgy components possess high compressive strength.

Dis-Advantages of Powder Metallurgy:

• Powder metallurgy components are expensive compared to General alloy formation method.
• Difficult to produce large & complex shapes with uniform density.
• Tensile strength is low.
• Al, Mg, Sb, Bi, As Ti powders, should not be used because they will undergo explosion at the time of compaction.

Markets for Powder Metallurgy components

• Around 80% of automotive applications are from powder metallurgy.
• 75% of components are used for transmissions.

Future scope of Powder Metallurgy Process

• Lightweight technology and engine downsizing in Automotive fields.
• Hitachi chemicals:
• Engaged in the development of wear-resistant parts, structural parts, magnetic parts (soft magnetic materials) for the development of high-performance parts as next-generation products.

Applications of powder metallurgy

• They are used for making cutting tools and dies.
• Used in making of machinery parts
• Powder metallurgical components are widely used in making bearings and bushes due to its self-lubricating property.

MOHAMMED SHAFI

Mohammed Shafi is a Mechanical Engineering Blogger by Passion and Assistant Professor by Profession. He want to Share his knowledge to the Young People by Presenting the GATE Sessions and all the concepts of Mechanical Engg. in a detailed way so that they can get best jobs in the future. For more info, Visit www.mechanicalstudents.com