Powder forming is predicated on the technically and commercially useful concept of sintering: densifying a powder into a solid article at a temperature well below its melting point. The primary benefits of powder forming are:

• Reduced forming temperature and thus cost
• Capability for engineered porosity
• Elimination of mold to component high-temperature interactions caused by melt forming
• Suitability for mass production of small metal components and ceramics of all shapes and sizes

Most metals are sintered at 70–80 % of their melting point, some refractory metals up to 90 %. High purity ceramic sintering temperatures sometimes approach 90 % of melting point, but with the widespread use of sintering aids, liquid phase sintering, and traditional ceramics with their broad compositional range, ceramic sintering is usually closer to 70 % of the melting point. The powder-forming process contains four basic steps:

1. Powder preparation.
2. Powder mixing, blending, and/or slurry preparation (a powder–liquid suspension is known as a slurry).
3. Forming.
4. Sintering.

The origins of powder forming date back at least 20,000 years, as shown from

the archaeological evidence of the first clay crockery. Today, apart from the glass

industry, all ceramics are formed by a powder-forming approach. This is because

the extremely high melting point of ceramics makes casting from a melt commercially

unviable unless driven by a strong commercial imperative. The only significant

exception to this is fuse-cast refractories, which are used in glass-forming

furnaces. In contrast, metal fabrication is predominantly via melt forming, with

powder metallurgy (PM) forming a smaller subset of metal forming, practiced only

when it brings commercial benefit. Ceramic and metal powder forming, while they

share many common traits, also have significant differences, primarily because of

two key differences:

1. Ceramic powders are hard and their products brittle, while metal powders are plastic and their products ductile.
2. Ceramics are generally in their highest oxidation state and can be sintered in air, while metal sintering generally needs a vacuum or a protective atmosphere.