Design and Validation of Elastic Dies for Enhanced Metal Powder Compaction: A FEM and Experimental Study

Area of Science:

• Materials Science
• Mechanical Engineering
• Powder Metallurgy

Background:

• Rigid dies in powder metallurgy face challenges like high ejection forces, density variations, and tool wear.
• Elastic-sleeve dies offer a novel solution by providing controllable radial confinement and elastic relaxation.

Purpose of the Study:

• To investigate the effectiveness of an elastic-sleeve die concept for metal powder compaction.
• To quantify the influence of key design parameters on compaction performance and tool wear.

Main Methods:

• Experimental compaction of Fe-based and 316L powders using an elastic-sleeve die.
• Finite element analysis (FEA) using SolidWorks Simulation and Marc Mentat for validation.
• Systematic variation of taper angle (α) and axial pretension (Δh).

Main Results:

• Increased contact pressure with taper angle up to α = 3° (≈200 MPa).
• Achieved high relative densities (ρ ≈ 0.889 for 316L, ρ ≈ 0.865 for Fe-Cu-C) with optimal parameters (Δh = 1.5 mm).
• FEA validated experimental results, showing density-force trends within ≈±5% error.

Conclusions:

• An optimal design window (α ≈ 3°, Δh ≈ 1.0-1.5 mm) maximizes densification and contact pressure.
• Elastic relaxation during extraction reduces ejection effort, enhancing tool life.
• Elastic dies present a practical advancement for powder metallurgy processes.