Hydropulsor HVR Case Study

Hydropulsor performed a case study to confirm HVR results first published by Höganäs AB. According to several of their published papers, Höganäs obtained densities as high as 7.7g/cc using a Hydropulsor HYP35-4 HVC powder compaction press in a double press, double sinter process.

In the Hydropulsor case study, Astaloy 85 Mo base powder with 0.5% graphite and 0.8% Kenolube was used. The relatively high percentages of additives limited the theoretical green density to 7.4 g/cc. As a result, densities higher than 7.3 g/cc could not be obtained using only the HVC press system (see Diagram 1).

A series of samples were compacted on a Hydropulsor HVC press system to an initial density of 7.0 g/cc. These samples were then pre-sintered and re-pressed using Hydropulsor’s HVR technology, as indicated by the black connecting line in Diagram 2. The red curve in Diagram 2 represents the samples after HVR re-pressing; and as shown in the chart, a density of 7.7 g/cc was obtained using compaction pressures comparable to HVC. In addition, Diagram 3 shows HVR is a very energy efficient technology in that it requires a lower level of impact energy to achieve higher densities.

Diagram 1: Density as a function of compaction pressure for HVC	Diagram 2: Density as a function of compaction pressure for HVC and HVR
Diagram 3: Density as a function of kinetic impact energy for HVC and HVR	Picture 1:Typical component compacted by HVR to a density of 7.65 g/cc