Crafting Precision: The Fundamentals of Powder Metallurgy & The Crucial Role of Vacuum Inert Gas Atomisation (VIGA) Systems

Powder metallurgy (PM) is a manufacturing process that involves producing metal powders and forming them into useful products by various techniques including additive manufacturing (AM), Metal Injection Moulding (MIM), and Hot Isostatic Pressing (HIP) and other methods. Powder Metallurgy is a highly versatile and efficient technique used to create complex shapes and high-performance materials that would be difficult or impossible to produce using traditional methods and skillsets.

Fundamentals of Powder Metallurgy

Here’s an overview of the fundamentals of powder metallurgy and the importance of vacuum inert gas atomisation systems:

Powder Production: The process begins with the production of metal powders. Various methods are used, including atomisation, chemical reduction, electrolysis, and mechanical alloying. Atomisation, particularly gas atomisation, is one of the most common methods and one we will focus on for the duration of this article. During the atomisation process a stream of molten metal is broken up into fine droplets by a jet of gas or liquid, which then solidify into powder particles.

Blending and Mixing: Once the powders are produced, they are often blended and mixed to achieve the desired material properties and uniformity. Lubricants or binders may also be added to improve the handling and compaction of the powders.

Compaction: The blended powder is compressed into a desired shape using a die. This compaction step forms a “green” part, which has the shape of the final product but lacks the necessary strength and density. The main methods for compaction include Uniaxial Pressing and Hot Isostatic Pressing (HIP). PSI’s first atomiser was developed to produce powder for the then emerging HIP industry in the 80s.  

Sintering: The green part is heated in a controlled atmosphere to a temperature below the melting point of the base metal. This process bonds the powder particles together, increasing strength and density, reducing porosity, and enhancing electrical and thermal conductivity.

Post-Processing: Additional processes such as forging, machining, heat treating, and surface finishing may be applied to achieve the final properties and dimensions. Heat treatment can further modify the microstructure and properties of the components, whilst infiltration and impregnation involve adding materials to fill the pores to enhance specific properties such as strength and corrosion resistance.

Versatile & Efficient Manufacturing

Powder metallurgy is a versatile and efficient manufacturing process that produces high-quality components with complex shapes and desirable material properties. It involves the production of metal powders, their compaction into shapes, sintering to bond particles, and any necessary secondary operations to achieve final specifications. The invention and refinement of gas atomisation systems to produce high-quality spherical metal alloy powders has allowed the continuing advancements in technology for varying applications such as Hot Isostatic Pressing (HIP), Additive Manufacturing (AM), Metal Injection Moulding (MIM) and more. Let’s explore the importance of the VIGA systems contribution to Powder Metallurgy.

Importance of Vacuum Inert Gas Atomisation Systems

Vacuum inert gas atomisation (VIGA) is a specialised technique used to produce high-quality metal powders, particularly for high-performance and reactive materials. PSI have developed a core range of gas atomisation systems to manufacture high-quality spherical powders for various industries including Additive Manufacturing, Energy Storage and Aerospace.  

Here’s why VIGA systems are important:

High Purity: Atomisation in a vacuum environment minimises contamination from gases such as oxygen, nitrogen, and hydrogen. This results in powders with high chemical purity, which is critical for applications demanding high-performance materials.

Controlled Atmosphere: Using inert gases (such as argon or helium) in the atomisation process prevents the oxidation of the molten metal. This is especially important for reactive metals and alloys, such as titanium and aluminium, which readily form oxides that can degrade material properties.

Fine and Uniform Powder: VIGA systems allow for precise control over the atomisation parameters, leading to the production of fine and uniform powder particles. This uniformity is essential for achieving consistent material properties and predictable behaviour in the final product.

Versatility: VIGA can be used to produce powders from a wide range of metals and alloys, including those that are difficult to melt and atomise using other methods. This versatility makes it a preferred choice for advanced applications such as aerospace, biomedical implants, and additive manufacturing. PSI support these critical industries with their VIGA technology, developed specially for complex novel alloys.

Improved Mechanical Properties: The high-quality powders produced by VIGA systems contribute to improved mechanical properties in the final products. This includes enhanced strength, hardness, and resistance to wear and corrosion. These enhancements in mechanical structures can be critical for applications such as marine components which must be corrosion resistant to prevent damage from sea water.

Advantages of Powder Metallurgy

Powder metallurgy has some huge advantages in the manufacturing industry such as materials utilisation, minimising waste production and creating a “greener” material cycle. This “green” manufacturing status can be attributed to the differences in manufacturing methods which can see PM as more cost effective than CNC or manual machining, due to the lower material waste and the lower labour costs. However, this is only true if the overall waste produced during AM production can be recycled or re-processed for further applications. Complex geometries and tolerances can also be achieved through PM processes which otherwise would not be achieved through traditional machining, see our article on near-net shape components for more information on PM applications.

Applications of Powder Metallurgy

Powder metallurgy is used in various industries and applications, including:

Aerospace: High-performance components such as turbine blades and structural parts.

Automotive: Engine components, gears, and bearings.

Medical: Biomedical implants and surgical instruments.

Energy: Components for nuclear reactors and energy storage systems.

Tooling: Cutting tools, dies, and wear-resistant parts.


Powder metallurgy is a critical manufacturing process for producing high-quality metal components with complex shapes and specific material properties. Vacuum inert gas atomisation systems play a crucial role in this process by producing high-purity, fine, and uniform metal powders, which are essential for advanced applications across various industries.

Our technical knowledge of VIGA systems and rapid solidification techniques have been developed over the last 40 years in the industry. PSI’s founding mission was to convert the theories of materials processing into engineering plants for the production of advanced materials. The company now produces machines for atomising metal to powder, PVD systems for turbine blade coatings, melt spinners for magnetic materials and CVD furnaces for ceramic fibre reinforced composites.

Looking to invest in a gas atomiser system? Why not contact us today for more information on gas atomisation technology or rapid solidification processes. | 01323 449001

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