Green Body Behaviour of High Velocity Pressed Metal Powder

Abstract

High velocity compaction (HVC) is a production technique with capacity to significantly improve the mechanical properties of powder metallurgy (PM) parts. Several investigations indicate that high-density components can by obtained using HVC. Other characteristics are low ejection force and uniform density. Investigated here are green body data such as density, tensile strength, radial springback, ejection force and surface flatness. Comparisons are performed with conventional compaction using the same pressing conditions. Cylindrical samples of a pre-alloyed water atomized iron powder are used in this experimental investigation. The different behaviour of HVC-pressed green bodies compared to conventional pressed green bodies are analysed and discussed. The HVC process in this study resulted in a better compressibility curve and lower ejection force compared to conventional quasi static pressing. Vertical scanning interferometry (VSI) measurements show that the HVC process gives flatter sample surfaces.

The effect of impact compaction on surface quality of powder discs

“…The HVC process in this study resulted in a higher compressibility compared to CC, that is, for the same maximum pressure a higher density is reached for HVC than CC. See [6] where this is described in more detail.…”

“…A number of investigations of the HVC process have been published recently. All publications indicate that high-density components can be obtained using HVC [2][3][4][5][6][7]. Other characteristics are low spring back, low ejection forces and uniform densities.…”

Experimental studies and modelling of high-velocity loaded iron-powder compacts

“…A number of investigations into the HVC process have been published in recent years. All publications indicate that high-density components can be obtained using HVC [1][2][3][4][5][6]. Other characteristics are low spring back, low ejection forces and uniform densities.…”

Effect of particle size distribution on green properties during high velocity compaction

“…Although some studies of the HVC technique had been published in the recent years [5][6][7][8][9][10], the influence of particle size distribution on green properties has not been studied. The iron powders with two different particle size distributions were pressed by HYP35-7 High Velocity Compaction Machine.…”