Structural properties and stability of the betaine-urea natural deep eutectic solvents

Plant science

SOME OBSERVATIONS ON PRESSURE DISTRIBUTION AND DIE FAILURE MODES IN HOT EXTRUSION

Extrusion is listed as a compressive deformation process in the classification of deformation practices given under DIN 8582 and 8583, and is usually carried out as a discontinuous process. In order to minimize defective products through proper die design and process control, a systematic analysis of extrusion process and tooling is thus required. To understand the process, and to determine optimum equipment and tooling requirements, the most important factor to be analyzed is perhaps the extrusion force or pressure. Due to the high temperatures involved, and because of the complex thermo-mechanical changes occurring, commercial hot extrusion is a complicated process. Any analysis would thus depend upon some or all of a number of parameters such as billet material, die material and geometry, ram velocity, working conditions, and complexity of die shape. This paper presents some results of ongoing studies about prediction of extrusion pressure and failure of dies in hot aluminum extrusion. The first part of the paper focuses on the inter-relationships of various basic parameters related to pressure variation. The second part describes some related product defects. In the last part, effect of die profile on modes of die failure is investigated