The main objective of this work was to design a novel device for compaction of metal powders so that the green parts could be ejected with applying a negligible force and without the need for any lubricant in either an admixed form or applied to the die wall. For this purpose a 40 mm diameter one-piece die was envisaged which would elastically contracted 0.076 mm before compaction and after com...

 One of the surface defects that arise in sheet metal working is when the part removes from the die. Since there are no external forces to make this defect, the origin of such fail is known as residual stress. Residual stress can develop in sheet metal forming due to non uniform deformation. In this paper, the workpiece is carbon steel with different volume fractions and arrangement of ferrite ...

Deformation behaviour during loading and unloading is studied in compression of an aluminium plate with a high ratio between the diameter thickness by DLC coated die. A compressed becomes thinner after to larger reduction loading. The plastic deformation confirmed measuring increase unloading. optimum profile die crown approaches reverse shape elastic deflection flat at stroke end increasing th...

In any metal forming process, both the strain rate and deformation rate depend on the die profile. The die profile also, is responsible for the non-uniformity of the deformation along the cross-section. These affect the quality and mechanical properties of the product. Therefore, if a die is designed, in which the affecting variables can be controlled spontaneously it is hoped to obtain a produ...

determination of the deformation length is one of the first steps in roll forming design. roll forming industries are very interested in explicit simple relationsfor prediction the deformation length without using trail-and-error methods at workshop or time consuming finite element simulations. in this paper, elastic properties and work-hardening behaviour of the strip are considered in additio...

cold rolling process of a major transformation in the form of sheet metal and a wide range of steel products are produced in this way. elastic deformation during cold rolling working rollers and the inevitable increase in the rolling force. in this study, the effect of elastic deformation during cold rolling mill rollers working on the reciprocating back and forth in tandem with the presence of...

-A broad-band acoustic emission detection system has been used to record the transient surface displacements due to the release of elastic waves during deformation and fracture of EN3OA. a low-alloy steel. Acoustic emission signals were recorded from material tested in the quenched, tempered and temper-embrittled conditions: Tests were also performed upon material which had been hydrogen charge...

Drawing of square section rod from round bar can be done with two die shapes. In the first die shape, deformation starts from corners of the square and in second die shape, deformation starts from sides of square. This article has compared the drawing force for both die shapes and as a result optimum die shape was determined. Due to complexity of metal flow inside the die, analyzing of actual p...

in a closed die forging process, it is impossible to form complex shapes in one stage, and thus it becomes necessary to use preform dies. in the present study, backward deformation method and fe simulation via abaqus software has been used in order to design preform die of the h-shaped parts. in the backward deformation method, the final shape of the part is considered as a starting point and u...