In this paper three-dimensional finite element method analysis and experimental flashless cold forging of aluminium front and back hubs, and the blade of an autonomous underwater vehicle propeller are presented. The rigid—plastic finite element simulation is performed using Deform F-3V6.0, to estimate the optimum load required for the flashless cold forging. The complex profiles of the hubs and blade are modelled using Solidworks SP4.02007, which is also used for the modelling of the workpiece and die-punch assembly. The workpiece used is of AISI AL6061 and the die material is die steel (AISI D2). The process is optimized to form the propeller back and front hubs, and the blade. For all the models, three workpieces with different specifications are selected and investigated to obtain the optimum workpiece that gives flashless cold forging with no underfilling. Based on the simulation results, the flashless cold forging is successfully done on a 100 tonne C-type machine. The experimental forged samples conform well with the simulated models.

Finite element (FE) method is extensively employed in solving linear and non-linear problems and widely used particularly in analyzing a forming process. It enables the analysis on internal properties such as stress effective, forming load, metal flow and deformation to be performed, in which results in an increase on the performance of forging process. Heading process which is often performed in conjunction with other cold forging process has been simulated by FE-code DEFORM TM F3 v6.0. The numerical results were analyzed to evaluate the effect of the fillet size and the friction value on the cold heading process. It was found that the heading process provided good precision and productivity as the size of fillet was increased; due to intensification of the metal flow to infuse the die cavity. On the other hand, the friction value also played an important role in governing the reaction force between workpiece and punch in the process.

In this work, computer-aided finite element analysis to determine conditions for flashless cold forging of a connecting rod is presented. The workpiece specifications were calculated by developing mathematical relations between the volumes of the die cavity and workpiece. The three dimensional FE simulation was made using DEFORM-F3 V 6.0 and geometrical modeling of the die and workpiece was performed with SOLIDWORKS 2007 4.0. The workpiece modeled was of AISI 1045 steel and the die material was die steel (AISI D2). The aspect ratios for the bigger eye, smaller eye and column of the connecting rod were optimized to obtain the minimum flash volume without underfilling. Three workpiece geometries were modeled: cylindrical, pre-form 1 (dumbbell shape with fillet) and pre-form 2 (dumbbell shape without fillet). Pre-form 2 was found to be the optimum workpiece to obtain flashless forging without underfilling, while minimizing the material volume and forging load.

No abstract

No abstract