STAGE 1. PREP – Plasma Rotating Electrode Process System
AMT.PREP.NI
AMT.PREP.TI
The Plasma Rotating Electrode Process System (PREP) is designed for the production of highly spherical metal powders with low O2 content from titanium and nickel base alloys by centrifugal atomization of wrought or cast rotating feedstock bars via plasma-melting in an inert gas atmosphere.
The PREP-based system is intended for high-quality metal powder production for HIP and additive manufacturing used for manufacturing critical parts, where high sphericity, very low entrapped gas porosity, stable powder morphology and process cleanliness are essential.
The PREP system design is based on the advanced theory of the powder particles formation during plasma melting of the rotating electrode and combines the process of centrifugal atomization of a high-speed rotating metal bar’s end face melted by a plasma torch in an inert gas atmosphere, generating spherical powder particles with high morphological quality and low gas porosity. The narrow PSD is mainly controlled by the rotation speed of the atomized bar. The molten metal is dispersed by centrifugal force into droplets that solidify inside the process chamber to form spherical metal powder particles suitable for downstream classification, powder handling and use in additive manufacturing, and PM HIP for critical-component applications.
The supplied configuration includes a high-speed drive providing up to 40,000 rpm of the bars, an independent plasma torch, a closed-loop water-to-water cooling system, Helium-Argon process gas system with regeneration of the gas, and automated process control.
Key Technical Data
Equipment designation
Plasma Rotating Electrode Process System (PREP)
Declared purpose
Production of metallic powders from titanium and nickel base alloys by centrifugal atomization of plasma-melted rod in inert atmosphere.
Raw material
Titanium alloys
Nickel base alloys
Nominal metal bar rotation speed
Up to 40000 rpm
Drum rotation speed
Up to 10000 rpm
Maximum number of loaded feedstock bars
100
Feedstock bar diameter
Ti alloys: Standard 55±0.1 mm, possible 55-57 mm
Ni based alloys: Standard 78±0.1 mm, possible 76-80 mm
Feedstock bar length
720 mm
Straightness
0.05 mm
Roundness
0.025 mm
Cylindricity
0.025 mm
Surface roughness along generatrix
Ti based alloys: < Ra 0.8
Ni based alloys: < Ra 1.2
Surface roughness of end faces
Ti based alloys: < Ra 1.6
Ni based alloys: < Ra 3.2
Internal diameter of melting chamber
2670 mm
Rotation drive type
Asynchronous
Productivity
Not less than 3 raw bars per hour
Working atmosphere
Helium-argon mixture (9:1)
Plasma melting system
With independent heating source – plasma torch
Power supply
380 V, 50 Hz, installed power 300 kW
Nominal plasma torch power
Nominal 120 kW, maximum 140 kW
Arc current
800-1600 A
Vacuum system
5×10-5 mmHg, pump-down time 40 min
Cooling system
Modular closed-loop water-to-water system
Inert gas system
Special combined modular gas system
Automation / Control
Automatic mode with setting and monitoring of required operating parameters
Claimed powder result
Metal alloy powder finer than 80 microns above 75%
Claimed non-metal inclusions
Up to 6 particles per 1 kg of powder
PREP system, Plasma Rotating Electrode Process, plasma rotating electrode atomization, spherical titanium powder, spherical nickel base alloy powder, metal powder for additive manufacturing, centrifugal atomization in inert gas, high-sphericity powder, low-porosity metal powder