Warm compaction is a process leading to parts with high green strength and density. An increased compacting temperature lowers the flow stress of the metallic particles and increases their ductility, resulting in higher powder compressibility and stronger interparticles bonding, either mechanical or metallurgical. Although many studies have been published on warm compaction, very few investigat...

The cold compaction of an aggregate of powder is treated from the viewpoint of crystal plasticity theory. The contacts between particles are treated as compaction planes which yield under both normal and shear straining. The hardening of each plane represents both geometric and material hardening at the contacts between particles; the macroscopic tangent stiffness can be written in terms of the...

The main objective of this work was to design a novel device for compaction of metal powders so that the green parts could be ejected with applying a negligible force and without the need for any lubricant in either an admixed form or applied to the die wall. For this purpose a 40 mm diameter one-piece die was envisaged which would elastically contracted 0.076 mm before compaction and after com...

This paper proposes a new foaming technology (solid-state foaming) to produce structural foams from waste thermosetting resins. The proposed technology is easy and does not require specific and expensive equipments. Solid tablets are produced by cold compaction of resin powder, and foam by heating in an oven. Composite foams can be produced by mixing fillers and resin powder before the cold com...

By analyzing spatio-temporal characteristics of short optical pulses diffusively transmitted through compacted granular materials, we reveal that powder compaction can give rise to strongly anisotropic light diffusion. Our disclosure represents a revision of the understanding of optics of powder compacts. Routes to material characterization and investigation of compression-induced structural an...

Characterization of the pore structure of compacted and sintered parts made from a nickel-base powder was accomplished using the mercury porosimetry method. The theoretical density values for the sintered specimens varied from 56.3 to 96.7% which corresponds to a porosity of 43.7 to 3.3%. A maximum interconnecting median pore diameter of 21 mum resulted from a -80/+200 mesh powder compacted at ...

Abstract—Powder metallurgy (P/M) is the only economic way to produce porous parts/products. P/M can produce near net shape parts hence reduces wastage of raw material and energy, avoids various machining operations. The most vital use of P/M is in production of metallic filters and self lubricating bush bearings and siding surfaces. The porosity of the part can be controlled by varying compacti...

A predictive model for powder compaction has been developed that incorporates unprecedented flexibility to design powder press tooling and reliable powder pressing processes. Sandia’s finite element (FE) toolkit comprises the heart of the modeling software, and a unique concept was developed to design a variable dimension and parameter template to easily build/design dies/components on a comput...