Powder Metallurgy - MET 143 Lecture Review

Flashcards covering key vocabulary and concepts from the Powder Metallurgy lecture to aid in exam preparation.

Powder Metallurgy (PM)

A manufacturing process that compacts fine particles into a desired shape and then heats them to form a bond.

Sintering

A process where the green part is heated below the melting point to bond the particles together.

Compaction

The initial step in powder metallurgy involving pressing metal powders into a mold to create a 'green part'.

Green part

The compacted but not yet sintered part in powder metallurgy.

Atomization

The most common method for producing metal powders by dispersing molten metal into fine particles.

Isostatic pressing

A compaction method that applies uniform pressure from all directions using a flexible mold.

Hot isostatic pressing (HIP)

A variant of isostatic pressing carried out at elevated temperatures to achieve finer microstructures.

Cold isostatic pressing (CIP)

Isostatic pressing performed at room temperature.

Mechanical alloying

A process that uses mechanical energy to mix two or more metallic powders into a homogeneous material.

Controlled porosity

A beneficial characteristic in some parts that allows for higher lubricant retention in applications like bearings.

P/M Advantages

Superior microstructures, consistent properties, low scrap, and the ability to achieve complex shapes.

P/M Disadvantages

Presence of shrinkage, potential corrosion due to porosity, and challenges in achieving certain design constraints.

Metal Powder Production

The methods used to create metal powders, predominantly through atomization and mechanical milling.

Densification

The process of reducing the void space in the powder mass during sintering, increasing the density of the final part.

Lubricants in P/M

Additives used during compaction to reduce friction between powder particles.

Properties of Sintered Parts

Including strength, density, and microstructure, which can vary greatly based on the sintering process.

Design Considerations of P/M

Factors such as avoiding sharp corners and accounting for shrinkage when designing parts for powder metallurgy.

Additives

Substances added to powder metallurgy processes to enhance properties such as lubricity and deflocculation.

Extrusion

A method of forming parts by forcing material through a die to create uniform cross-sections.

Altering material properties

Depending on compaction techniques, the strength and characteristics of the final product can change significantly.