PM compaction equations applied for the modelling of titanium hydride powders compressibility data

Abstract

The suitability of compaction equations commonly used in PM was investigated for the modelling of TiH 2 powder compaction. Compressibility data of TiH 2 powder fractions (<45, <150 and <355 μm) were obtained up to 800 MPa and fitted to the Heckel equation, as well as to the models of Gerdemann and Jablonski and Cooper and Eaton. Although a partial correlation was observed for the Heckel equation, the model provided a consistent approximation of TiH 2 powder yield strength. An accurate fit was observed for the Gerdemann and Jablonski equation; however, considering the brittleness of TiH 2 , a more realistic depiction of the physical process was verified from the Cooper and Eaton model. By the addition of an exponential term to the original equation an excellent fit was attained, and compaction of TiH 2 powders could be appropriately described according to the mechanisms of initial density, particle rearrangement, fragmentation and plastic deformation.

Study on Compaction and Machinability of Silicon Nitride (Si3N4) Reinforced Copper Alloy Composite through P/M Route

“…Powder metallurgy is a versatile process of producing composites within a short period. The preparation of powders, blending of powders, and the compaction process are indirect effects of the composites' machinability process [5][6][7]. The sintering process increases the strength of the composites and affects the cutting force of the tool.…”

Comparative Study on Cold Compaction Behavior of TiH2 Powder and HDH‐Ti Powder

“…Contrary to ductile metals, the compaction behavior of brittle TiH 2 powder is similar to that for ceramic materials, based mainly on particle rearrangement, crushing, and fragmentation mechanisms, with relatively low, if any plastic deformation contribution [23,24]. Although there were some studies on the mathematical modelling of TiH 2 powder compaction, such modelling only predicts the trend of compaction behavior, and the analysis of the compaction behavior of TiH 2 powder is not deep and complete [15,25,26]. In order to be able to truly reflect the compaction characteristics of TiH 2 powder, this study will analyze it through more systematic analysis methods.…”

“…In order to better analyze the compaction behavior of TiH 2 powder, besides the relative density, fractional volume V * parameter has been used. Parameter V * was introduced by Petroni [25] as that associated with the filling of pores at a giving pressure P (pores reduction rate, i.e., decrease in relative pore volume under pressure P applied):…”

Evaluation and parameter analysis of compaction equations applied to titanium powder

“…At the same time, Fischmeister [33] also pointed out that according to the compaction equation and powder characteristics, the contribution to the densification process of powder mainly includes the initial apparent density of powder before compaction and the contribution of particle rearrangement and particle work hardening during compaction. The degree of these contributions differs among various powders [30,34]. Therefore, in addition to the simple data fitting of the powder compaction equation, scholars are also constantly analysing the compacting behaviour of the powder based on the compaction equation.…”

“…k 1 and k 2 have pressure units and they reflect the magnitude of pressure where each compaction step has the greatest probability [40]. Petroni [34] recently optimised Equation (3) by adding an initial density term as follows:…”