Page 53 - Vol_1_Chapter_III

• Secondary Operations (Optional): Depending on the desired properties and specifications, secondary operations such as heat treatment,
machining, and surface finishing may be performed after sintering to achieve the desired final characteristics.
• Key characteristics and advantages of powder metallurgy include:
• Complex Geometries: Powder metallurgy allows for the production of intricate and complex shapes that may be difficult or impossible to
achieve through traditional methods like machining.
• Controlled Properties: Powder metallurgy provides control over material properties like density, hardness, and porosity by adjusting factors
such as powder composition, particle size distribution, and sintering conditions.
• Material Efficiency: PM generates minimal waste since the starting material is in powder form, reducing machining scrap.
• Versatility: A wide range of metals and alloys can be processed using powder metallurgy, including ferrous and non-ferrous metals, stainless
steels, tool steels, copper, aluminium, and more.
• Cost-Effectiveness: For certain applications, PM can be cost-effective, especially for producing parts in large quantities or parts with complex
geometries.
However, powder metallurgy also has some limitations:
• Size and Shape Constraints: Extremely large or complex parts may be challenging to produce using PM.
• Limited Mechanical Properties: While PM produces parts with good strength, some traditional manufacturing processes may yield even higher
mechanical properties in specific cases.
• Equipment and Expertise: Specialized equipment and expertise are required for powder production, blending, compaction, sintering, and
secondary operations.
Powder metallurgy finds applications in various industries, including automotive, aerospace, electronics, medical devices, and more. Components
produced using PM include gears, bearings, bushings, engine parts, cutting tools, and magnets, among others.
Casting and Casting and moulding are manufacturing processes used to create objects by pouring or injecting a material into a mold or cavity, allowing it to
Moulding solidify and take on the desired shape. Both processes are widely used in various industries to produce a wide range of products, from intricate
parts to large-scale objects.
Casting
Casting involves pouring a molten material, typically metal or plastic, into a mould to create a solid object as the material cools and solidifies. There
are different types of casting processes, each suited to specific materials and applications:
• Sand Casting: In sand casting, a pattern of the desired object is placed in sand to create a mould cavity. Molten metal is poured into the mould,
and once it cools, the sand is removed to reveal the cast part.
• Investment Casting: Also known as "lost wax casting," investment casting uses a wax pattern that is coated with a refractory material. The (Source of images:
wax is melted out, leaving a cavity that is then filled with molten metal. https://mellowpine.com/blog/casting-vs-
• Die Casting: Die casting involves forcing molten metal under high pressure into a mould cavity, often made of steel. This process is used to molding/)
produce parts with high dimensional accuracy and surface finish.
• Centrifugal Casting: In centrifugal casting, the mould is rotated to force the molten metal into the mould cavity. This process is used to create
cylindrical shapes.
Moulding
Moulding is a process used to shape materials such as plastics, rubber, or composites by injecting them into a mould. There are various moulding
methods, each tailored to specific materials and requirements:
• Injection Moulding: In injection moulding, molten plastic is injected into a mould cavity. Once cooled, the plastic solidifies and takes on the
shape of the mould.

Copyright © by DIGIGREEN All Rights Reserved Volume I – Chapter III: Digital and Green Machining and Forming 37