Expertise in materials essential for designers
(Article by Jessica Vermeer, ‘Mechatronica & Machinebouw’ – June 2020)
Invar and Duplex were the subjects under discussion at the half-yearly colloquium on materials of Hittech University this year. Cor Heijwegen talks of the importance of materials for hi-tech Netherlands.
The pencils are sharpened and the folders are ready and waiting as we’re going to school today. To Hittech University, that is. Cor Heijwegen, co-founder of the Hittech Group, established the in-house University several years ago. One of the activities the company organises, is a half-yearly colloquium on special materials. Clients, such as ASML and VDL ETG, as well as designers and operators from within Hittech, make up the guest list.
The most important goal of the colloquium is to increase the expertise in materials and to bring together knowledge and experience. In addition, Hittech wants to confront the designers with the problems associated with the choice of material for an application and explain to them that they must have a basic knowledge in order to make the correct choice. ‘According to us the knowledge level should be increased’, Heijwegen explains. ‘Designers must be aware of the factors to be taken into account. They must ask the right questions in a very early stage of the development process. The developers must know which expert to go to and to understand all that he is saying.’
A second goal is to link the scientific theory to practice. Hittech will select one or two materials, which will be subject to an in-depth discussion during the colloquium. The last time it was titan and this time it’s about Invar and Duplex. Hittech also invites clients. ‘It makes for a good interaction’, according to Heijwegen. ‘We have a great ongoing collaboration with the 3ME Department of Delft University of Technology whose professors and senior lecturers make an appearance at the colloquia.’ This time it was university senior lecturer, Erik Offerman, who provided an introduction to Invar and other nickel-iron alloys. In addition, professor Ulrich Krupp of RWTH Aachen, lectured on the machining, properties and failure mechanisms of duplex stainless steel. Koen Mentink, of Hittech Bihca, and Ard Geelkerken, of Hittech Multin, spoke about the machining of materials and value engineering respectively.
Hittech and Heijwegen are most definitely not the only ones in the hi-tech industry who feel that a higher level of material expertise among engineers is of great importance. Wrong choices can have substantial consequences. Representatives of Hittech, ASML, Thermo Fisher and VDL ETG, collaborated in writing a letter to the Dean of 3ME of Delft UoT at the end of 2018, in which they asked that more attention be paid to materials science in the curricula. This resulted in the establishment of a working group made up of representatives of Delft University and the industry. The aforementioned companies are currently giving guest lectures on the actual practice and provide subjects for projects.
A bond with materials
Before aiming for the hi-tech industry via Hittech, Heijwegen had already accrued a wide experience as entrepreneur. He started at Hoogovens in 1973 and became the Division Director of Hoogovens Industriële Toeleveringsbedrijven (HIT – Hoogovens Industrial Supply Companies) in 1989. After a Management buy-out in 1994, half of the division was taken over followed by the substantial expansion of the number of companies which were then divided into five groups. From 2000 onwards, four groups were sold. The last group, consisting of only three machine shops and a foundry, represented the start of the Hittech Group in 2004.
The lecture of professor Ulrich Krupp of RWTH Aachen was about duplex stainless steel.
‘We found the hi-tech industry to be extremely interesting’, Heijwegen explains. ‘It appealed to me to be at the front of technological development.’ It didn’t take long before companies were added to expand the competencies, but what never changed was the bond with materials from his Hoogovens’ past. After all, there’s a reason why the conference rooms at Hittech’s head office in The Hague were named after metals such as aluminium and titanium.
Thus, materials science and production are at the basis of Hittech forming the primary competencies. The disciplines of assembly and engineering were added with the acquisition of Multin. ‘We develop systems and subsystems with the intention of producing these ourselves’, Heijwegen explains. ‘We develop systems for customers within the context of manufacturability.’ This emphasises the importance of the materials colloquium. ‘The developers must be able to make the right choices in the design process. We excel in manufacturability and wish to put that into practice. But one can always do better. The material requirements of the hi-tech industry are continuously on the rise. Hence these colloquia.’
Early involvement and material expertise are essential in development. Ard Geelkerken elaborates on this during the colloquium. Geelkerken is Team Leader Value Engineering at Hittech Multin. One of his tasks is to involve suppliers in the development process early on. ‘In functional engineering all the attention usually goes to the prototype’, he explains. ‘Value engineering, however, focuses on the entire life cycle of a product.’
A designer bases his choices on his knowledge. The project leader determines the goal and wants to minimise the risks. The client wants to get to the market post-haste. Firstly, a product must meet the requirements, followed by quality and costs. ‘The designer will quickly opt for expensive materials and complicated shapes if it assures him that the prototype will work’, Geelkerken comments. ‘It’s not difficult to make the prototype. What he doesn’t know is how expensive the final production will turn out to be.’ It usually takes the first production series before it becomes clear that the costs are too high which results in discussions.
Delft UoT professor Erik Offerman provided an introduction on Invar and other nickel-iron alloys.
Engineers must keep tabs during the design process as to whether the end result will be satisfactory, from both a technical and economic perspective. ‘Everyone in the design cycle has their own speciality and philosophy’, Geelkerken states. ‘The designer strives for risk-free functionality and specifies the best of the best. The machining factories become enthusiastic and can manufacture everything within the tolerances. The operators are rewarded for repetitive quality where complicated components are concerned.’
This means that the designer must enter into talks with the machining and material expert early on in the process. Through value engineering, Geelkerken can already show the effect of material choices on the cost price during the design phase. He states: ‘Machining concepts and other constructions can prevent the use of expensive materials or production methods.’
Geelkerken provides a number of examples in which consulting during the design phase resulted in lower cost prices. In this way the thermal isolation of a spindle prevented the use of special, more expensive materials. For another component more than 20 percent of the machining time was spent on tiny details. The component had a deep pocket making it difficult to machine the inside. The design was changed into two separate parts, resulting in a cost reduction of 18 percent. ‘That’s quite something if you plan to scale up’, according to Geelkerken.
By using a clever design, a more expensive material with lower production costs can still result in a cost reduction. ‘If the increased attention results in lower costs during the design phase, you have a business case’, Geelkerken concludes. ‘So be creative in the selection of materials. Look at all that’s available and take advantage of the standard sizes of available materials. Initiate the discussion in the early design phase and include the production costs.’ After all, it’s all about the integral cost price.