A review of force reduction methods in precision forging axisymmetric shapes

Abstract

This paper provides a review of the methods developed over the years for reducing working forces for the precision metal forming processes. Precision forging normally involves completely, or near completely closed cavity dies with no or minimal draft, making features on the extremities difficult to fill and requiring high loads. Means to minimise load, in order to enhance tool life, or reduce press capacity are crucial to the success of precision forging processes. The main concentration of this study is on design features which can be incorporated in tooling and/or workpiece in order to assist in minimisation of forging load while achieving complete die filling. The load reduction methods are presented using examples mainly of precision gear forging, which is representative of the precision forging of other axisymmetric components with complex peripheral shape. The methods reviewed are divided into the categories of (i) billet design, (ii) tool design and (iii) process design. Their effects on forging load reduction for precision forging, along with the authors' opinions as to the benefits, drawbacks and applicability of each, are presented.

A review of manufacturing processes, mechanical properties and precipitations for aluminum lithium alloys used in aeronautic applications

“…Most products are obtained by forming processes such as extrusion (hot or cold), stamping, rolling (hot or cold) and forging (hot or cold) (“advancement in Forging Process,” 2017). Rolling and stamping processes are used for sheet metal processing (Vallabh Bhoyar and Swapnil Umredkar, 2020) [ 102 ]. Forging is a shaping process by hammering or pressing after hot softening.…”

Key features and novel trends for developing cost engineering methods for forged components: a systematic literature review

“…In scientific and academic literature there are no review papers focused on the estimation of forging costs, but only reviews focused on forging equipment, in particular on methods of increasing the life of forging tools [11,12] or on degradation mechanisms [13]. Other authors focused their research on force reduction methods [14], measurement techniques [15], material behaviour [16,17], or developments in a particular forged product [18]. The current review provides comprehensive coverage by reviewing 85 documents from 1970 until now.…”

Integrated modelling of hot forging of low-alloyed steels for an ICME workflow

“…The additive rule used is given in Eq. (12), where Δ i denotes the strain increment for ith increment and p,i denotes the value of p for that increment. Since different strain increments occur at different strain rates, it is justifiable to use such an additive rule in order to include the contribution of each plastic strain increment to the total strain energy needed for the incubation of nuclei for DRX.…”

“…Therefore, to obtain the desired properties, it is necessary to carefully design the process to yield the required microstructure distribution in the final product. Traditionally, process design in the context of hot forging has majorly been limited to address issues such as die designing [1,2], reducing underfill [3], avoiding possible defects [4][5][6], flash design [7][8][9], forging load [10][11][12] and more recently microstructure evolution [13][14][15][16][17]. Often, these approaches focus primarily on the deformation sub-step design without paying much attention on the role of the process in the larger product development workflow which includes material selection, other upstream and downstream processes and final property requirement.…”