Simulation-driven process design revolutionises metal forming technology
SOFTWARE & SYSTEMS NUMERICAL SIMULATION
QFORM GROUP
Simulation-driven process design revolutionises metal forming technology
By Nikolay Biba , MICAS Simulations Ltd , Oxford , UK and Pavel Mordvintsev , QForm Group FZ , UAE
Numerical simulation has become an indispensable tool for the development of metal-forming technology . It eliminates the need for expensive metal trials by accurately predicting the product shape and identifying technological defects . Nonetheless , the engineer must specify the parameters of the technological process and the shape of the deforming tools before the simulation starts . Thus , the search for the best technology still relies on an engineer ’ s skills and experience , even though they can now try different variants much faster .
Fig . 1 . The automatically created geometry shape for the top die cavity ( a ), the preform operation simulation ( b ), photos of the industrial defect-free aluminium preform and finished forged part before flash trimming .
With multi-stage forging or rolling processes through several passes , the real challenge is to find the best sequence of intermediate shapes between forging blows ( preforms ) or the sequence of roll grooves . In this case , we face the problem of finding the optimal workpiece shape transformation from the initial stock to the finished product . This transformation is not a simple alteration of some drafts or radii . We must consider the shapes of deformed workpiece and forming tools as the integrity of interconnected geometrical entities and alter them to achieve the best performance . The material volume constancy requirement also restricts the variation of the deformed workpiece . The creation of such intermediate shapes must be done using specialised CAD software that uses precise simulation as an optimisation and verification tool to
achieve the best performance , and this must be done using established technological process design rules and practical experience . With this approach , we came to the next level of manufacturing digitalisation , which is called the simulation-driven design of processes . Its outcome includes finish die fill , absence of material flow defects , minimum material loss , and guaranteed material workout , all while staying within the admissible load . We have special simulation-driven software products for aluminium profile extrusion , shape rolling , ring rolling and open-die forging , however here we illustrate our approach with an example of a hot closed-die forging .
Automated forging sequence design
In practice , very few forgings are produced in a single impression . Usually , one or two preforming
operations are necessary to transform the billet material into a shape that fills completely without defects in the finish die cavity . Our unique software , QForm UK Direct , develops a preform shape based on potential flow approximation . An explanation of the method and its history can be found in [ 1 ]. As an output , the program creates the optimal preform shape and the complete CAD model of the preforming dies . Then , this model can be verified by simulation and CNC machined for regular forging manufacturing , as shown by the complex aluminium forging example in Fig . 1 .
[ 1 ] N . Biba , A . Vlasov , D . Krivenko , A . Duzhev , S . Stebunov , Closed Die Forging Preform Shape Design Using Isothermal Surfaces Method , In Proceeding of ESAFORM 2020 , ISBN : 978-1-7138-1028-5 , pp . 268-273 .
For further information , please visit www . qform3d . com
114 PECM Issue 70