Manufacturing of Powder Metals

Next generation alloy development

Liberty Powder Metals are committed to R&D for next generation alloy development, and have a growing range of new alloys. Customisation options include powder size distribution, chemistry adjustment, and new alloy development are available upon request.

Confidence and certainty in the consistency and repeatability of the metal powders you choose

Utilising the full suite of powder characterisation and testing coupled with their unique optimisation processes ensures the quality of metal powders is consistently repeated.

Liberty Powder Metals provide powder metal to customers working in some of the most challenging and demanding, mission critical environments including aerospace, space, defence, medical, energy, automotive and precision engineering.

They deliver highly spherical metal powders that resuly in excellent flow and packing characteristics essential for metal Additive Manufacturing, PMHIP and near net shape production. All our metal powders are application optimised.

Powder Manufacture and Characterisation

Atomisation

Atomisation is a process in which a bulk liquid is broken up (typically using high pressure water or gas flow) into droplets. Although there are a number of emerging atomising technologies (such as ultrasonics, plasma atomisation and plasma rotating electrode process) the two main processes used to manufacture metal powder are gas atomisation and water atomisation. The aim of this section is to provide a brief introduction to the gas and water atomisation processes.

A typical atomisation process involves three main stages:

Melting pre-alloyed or pure metal ingots
Atomisation
Product recovery and classification

In the gas atomisation process high pressure gas is used to break the molten metal liquid into droplets. The gas source can be atmospheric gas or more typically an inert gas such as argon, nitrogen or rarely helium.

Gas atomisation can be used to produce almost all types of metal powder, and is typically used to manufacture powder for high end manufacturing technologies (HIP, AM, MIM) due to its ability to produce powder with highly spherical(ish) particles with an oxygen content comparatively lower than that of water atomised powder. Scanning electron microscope (SEM) images of a typical particles produced via the gas atomisation method are shown below.

Measurement Techniques

Internal

Characteristic	Method	Typical Standard(s)
Particle Morphology	Static Image Analysis	ISO 13322-1
Particle Size Distribution	Laser Diffraction	ASTM B822
Particle Size Distribution	Test Sieve Analysis	ASTM B214
Particle Density	Pycnometery	ASTM B923
Flow and packing properties	Tapped/apparent density	ASTM B527
Flow and packing properties	Hall/Carney Flow	ASTM B212/B213/B417/B964
Oxygen, nitrogen analysis	Inert gas fusion	Material specific
Carbon, sulphur analysis	Combustion infrared detection	Material specific

External

Characteristic	Method	Typical Standard(s)
Particle Morphology	SEM	-
Particle Morphology	Dynamic Image Analysis	ISO 13322-2
Hydrogen analysis	Inert gas fusion	Material specific
Bulk chemical analysis	ICP spectroscopy	Material specific

Manufacturing

From state-of-the-art facilities in the UK, Liberty Powder Metals provide vacuum inert gas atomisation in argon of steel, nickel and cobalt alloys deploying anti-satellite technology and plasma titanium and aluminium alloys.