Optimization of Metal Forming Processes

Our standard approach to optimizing a process in relation to material efficiency is as follows:

  • The customer provides LASSO ME with information about the materials and tools employed and the end product.

  • LASSO ME analyses the current process and establishes where the process could be improved e.g. reduction of process levels and the forming temperature or speed to achieve less waste. The load applied to the tools is also determined and suggestions are presented to reduce the load in order to increase the lifespan of the tools.

The optimization of metal forming processes and mechanical properties of products possesses huge potential to save material, energy and cost.

Load optimized components possess only as much material as necessary. For example, flexible rolling creates tin blanks which can be used to adapt the material distribution of the component load in operation. Most products in operation today have not had their load optimized. Flexible metal forming processes enable the manufactue of brand new products which are easy on material. Lasso ME has extensive experience in flexible metal forming processes and contact to other research institutes which also develop load optimized and custom-made products.

Load analysis of the product is a further method of saving potential. The component is placed on a virtual test bench which imitates all loads that occur during real operation. The result is a stress analysis which indicates where the component is oversized or too weak. Lasso ME can then calculate an optimized geometry of the component in relation to load and material usage. This can also increase the lifespan of a product. Lasso ME uses the program “…” to determine the lifespan.

Description of the computer aided optimization program CAOT

The main emphasis of the program package CAOT is on automatic evaluation of the results and automatic modification of the influencing parameters in order to improve the results. This optimization program requires a numerical model to illustrate the process which is to be optimized e.g. an FEM program or an empirical model (see diagram).

 

 

 

LASSO ME offers a commercial numerical optimization tool which the customer can easily use after receiving a short training from us.

Another possibility is to ask us to carry out the optimization.

The optimization method and some examples are described below.

Example 1: Optimization of a rolling process for heavy plates.

A badly designed process chain (e.g. rolling parameters) can lead to individual aggregates failing early in the process due to wear and tear. Optimization of the whole process chain corrects this problem and this in turn will lead to material and energy savings.

Optimization objective: uniform power in all 9 passes by variation of roll gaps.
Restrictions: rolling mill limits (F,P,W); definitive temperature in 7th pass and the final geometry.

Example 2: Optimization of a drawing process

Optimization objective: The key to saving material when drawing wires and rods lies in optimizing the design and the drawing tools. Minor modifications to the drawing geometry greatly improve the lifespan of the tools and the properties of the drawn products (e.g. reduction of adverse internal stresses or creation of useful compressive internal stresses in the surface).

By varying the design parameters, the tensile stress near the surface should be decreased without decreasing the compressive strain in the core.

range for tensile stress [0..800 N/mm2],
range for compressive stress [-800..-600 N/mm2].

 

Example 3: Optimization of an open die forging process

Optimization objective:
Reductions
of tensile stress by varying the tool geometry

Restrictions:
No deterioration in core structure

Example 4: Optimization of microstructure

Optimization objective:
homogeneous structure with more than 70% DRX-rate in critical zones by variation of the tool design.

Example 5: Optimization of a component

Many components use far too much material. Frequently up to 30% and more can be saved without compromising the functionality of the component.

Optimization objective:
Minimal deflection at the given force

Restriction: Weight is lower than in initial state (100%)