Gas-flow Refinement and Atomization Nozzle Design and testing for Efficient powder production
GRANDE project aims to make steel powder production more efficient and sustainable by improving the gas atomization process and reducing waste. The project will develop advanced nozzle design methods for high-performance powders used in Additive Manufacturing and Hot Isostatic Pressing, where production waste can reach up to 70%. By combining computational modelling, advanced flow diagnostics, and industrial-scale testing, GRANDE will enable precise control of powder characteristics while increasing productivity and reducing energy consumption. The expected results include significant cost and CO₂ savings, supporting a more competitive, resource-efficient, and sustainable European steel industry.
General Objective
Currently the atomization of steel ingots in finite powders can reach up to 70% of waste, due to the distribution of particle sizes around the desired parameters. Therefore, to achieve the desired product, several production batches are needed, increasing both product costs and energy demanding. Moreover, although steel is intrinsically recyclable, the high surface/volume ratio of these microparticles can result in modification of properties leading to low-quality scrap materials for subsequent remelting and reutilization, in particular for some steel grades whose performance strictly depend on their surface properties. In this context, GRANDE project proposes a retrofit-driven, kit-based approach to improve first-pass yields, which currently lies at 30–50%, thereby reducing costly re-processing, energy use and CO₂ emissions. Partners will co-develop modular nozzle designs and validated, physics-based predictive models to replace empirical, trial-and-error practices, enabling deterministic control of particle size distribution, powder morphology and microstructure from tunable process parameters.
State of art
1
Gas atomization is the most widely used technology for producing steel powders for Additive Manufacturing (AM) and Hot Isostatic Pressing (HIP), enabling the production of fine, spherical particles with high performance characteristics.
2
Despite its industrial maturity, the process remains inefficient, with production waste often reaching up to 70% due to strict particle size requirements and limited control over powder characteristics.
3
The design of atomization nozzles is still largely based on empirical knowledge and trial-and-error approaches, rather than on predictive scientific methods.
4
Current technologies offer limited capability to accurately predict and control the relationship between nozzle geometry, process parameters, and resulting particle size distribution.
5
Advanced computational modelling and flow diagnostic tools are available but are not yet fully integrated into industrial nozzle design and optimization practices.
6
There is a growing need for more sustainable and resource-efficient powder production processes that reduce material losses, energy consumption, production costs, and CO₂ emissions while meeting the increasing demand for high-quality metal powders in advanced manufacturing sectors.
Key Challenges in Nozzle Design
Controlling particle size distribution: The nozzle geometry strongly influences droplet formation and, consequently, the size and quality of the produced powder. Achieving the target particle size range remains a major challenge.
Optimizing gas-metal interactions: Efficient atomization depends on complex interactions between high-velocity gas jets and molten metal streams. Understanding and controlling these interactions is critical for process performance.
Reducing powder waste: Current atomization processes can generate large amounts of out-of-specification powder. Improved nozzle designs are needed to maximize the yield of usable particles
Balancing productivity and quality: Higher production rates often compromise powder characteristics. Designing nozzles that maintain powder quality while increasing throughput is a key objective.
Limited predictive design tools: Nozzle development is still largely based on empirical knowledge and trial-and-error approaches, making optimization costly and time-consuming.
Ensuring process stability: Small variations in nozzle geometry or operating conditions can affect powder morphology, flowability, and process efficiency, requiring robust and reliable designs.
Minimizing energy consumption: Optimized nozzle configurations can reduce gas usage and energy demand, improving both economic and environmental performance.
Scaling up from laboratory to industrial production: Designs that perform well at laboratory scale must be validated and adapted for industrial-scale manufacturing while maintaining consistent powder quality.