Investigations on dynamic compaction of metal powders: Part 1: Experimental

Abstract

used explosively powered projectiles to compact diVerent powdered materials. 4 -6 Petro Forge machines and similar This paper investigates the use of a simple drop weight equipments were also used for dynamic compaction process. 7 ,8 instrumented impact loading facility to produce metal Explosive isodynamic compaction also called direct powder compacts with better qualities than attained explosive compaction, is another type of dynamic comby the conventional means. Experiments were perpaction process. The powder to be treated is kept inside a formed on Fe powder, Fe-C-Cu-Mn powder mix, and container surrounded by an appropriate amount of explosive, Cu-Zn powder mix at diVerent height to diameter which on detonation implodes the container thereby comratios and compacted at diVerent energies. The overall pacting the powders. 9 -1 2 This method is useful only for density, density variation within the compact, dimencompacting the more diYcult to process hard metal powders sional accuracy, and microstructure were compared and cannot be used in a production line. Dynamic comwith quasistatic specimens compacted using convenpaction at high compaction rates cause interparticle welding tional hydraulic press. The results showed that the and hence produces strong compacts. 1 3 -1 5 Extensive work dynamic compaction specimens attained better densiwas carried out to analyse the microstructures and study cation and dimensional accuracy than quasistatic the processes leading to bonding in a range metallic powder compaction specimens.PM/0997 compacts. 1 6 -2 0 It was observed that very high localised and relatively high temperatures are achieved at particle surfaces The authors (rkkumar@iitm.ac.in) are in the and involve diVerent mechanisms during the compaction Manufacturing Engineering Section, Department of process. Mechanical Engineering, Indian Institute of TechRecent developments include dynamic compaction of nology Madras, Chennai 600 036, India. Manuscript titanium alloy powders. 2 1 -2 6 Densi cation behaviour of rapidly

Green Body Behaviour of High Velocity Pressed Metal Powder

“…A number of investigations of the High Velocity Compaction (HVC) process have been published in recent years [1][2][3][4][5]. All publications indicate that high-density components can be obtained using HVC.…”

Modelling the non-linear elastic behaviour and fracture of metal powder compacts

“…The main difference is the speed of the punches during compaction; see e.g. [1][2][3][4][5]. Green body cracks are primarily formed during compaction and ejection.…”

Sintering studies on iron-carbon-copper compacts

“…Hence in this present study, nitrogen atmosphere has been selected as the sintering protective atmosphere. [1] D. Roshan Kumar et al carried out experiments on dynamic compacting and quasistatic compacting of Fe, Fe-C-Cu-Mn powder and Cu-Zn powder and they have reported that densification and dimensional accuracy is better in dynamic compaction than quasistatic compaction. [2] D. Korachkin et al investigated the tensile failure of Distaloy AE ferrous powder and Alumina powder using three point bending test and diametral compression test and they have reported that ferrous powder showed a nonlinear increase in powder strength at higher density level whereas Alumina powder showed a linear increase in tensile strength.…”