Materials World’s 25th Volume

Materials World magazine
,
4 Jan 2017

To celebrate the first issue of Volume 25, we look back at three stories from the very first issue of Materials World, and examine how they compare to the news of today. 

Then – A new enhanced performance stainless steel 

In the first issue of Materials World, RG Hamerton, DM Jaeger and AR Jones from AEA Industrial Technology, UK, wrote about the company’s ‘novel austenitic stainless steel with considerably superior mechanical properties compared to conventional alternatives.’ 

The key to its performance, they wrote, was an extremely fine dispersion of titanium nitride particles less than 30nm in size. We sent a copy of this article to the Institute’s Iron and Steel Society for comment on its relevance today, and Professor John Dunkley, the recipient of the 2016 Ivor Jenkins Medal (see Materials World, September 2016, page 65) returned this expansive review of powder metallurgy (PM) in the interim years.

Now – Powder metallurgy since 1993

The article describes work that, as far as I know, never got much further. The plain fact is that a dispersion-strengthened material like this needs a vacuum melted, inert gas atomised powder, which is pretty costly, as are the subsequent stages of nitriding and compaction. Also, I fear that such alloys are not easy to weld, and weldability is a major factor in the popularity of austenitic stainless steels.

However, the uses of stainless steel powder have changed and expanded greatly over this time frame. Sadly, the largest scale process – the Anval Nyby process of the hot extrusion of tubes from gas atomised powder capsules – was abandoned, and the largest (6t) gas atomiser in the world at that time (and for most of the next 20 years) has been used for other stainless products. 

The range of applications is now pretty impressive. The 'classical' sintered PM stainless steels, in the form of cold pressed and sintered parts made from irregular, water atomised powders, started production in the 1960s and were well established by 1993. Since then, they have probably tripled in volume and I would estimate production of '100 mesh' stainless steel powders in Japan, USA and Europe is around 20,000t, worth around £40 million, a year. A much smaller, but technically important, sector is the manufacture of sintered stainless steel filters, which have also been produced for 40 years. 

A more rapidly growing market has been metal injection moulding (MIM) using very fine powders, typically with median particle sizes around 10μm ('100 mesh' powder is around 50μm). This started with gas-atomised fines in the 1980s, but the Japanese developed ultra-high pressure water atomisation, which was more economical and serious production built up in the late 1990s. Fierce competition and much R&D to raise yields of fines have reduced costs considerably and the market has been growing at nearly 10% annually for the last decade. That said, it has only reached around 5–10,000t/pa but, with prices still higher than coarser powders, this is worth around £50m. 

A less spectacular, but nonetheless important, field has been the consolidation of gas atomised stainless powders by hot isostatic pressing (HIP) to generate large components. As the cost of HIP has fallen, and the size of presses, and hence of possible parts, has increased. A sizeable market has developed for special parts for the oil and gas industry (sadly, now very depressed). This has been using volumes estimated to be in the 5–10kt/pa range. 

A very specialised field, in which the Swedes excel, is the use of powder to produce wrought material. While the Anval Nyby process has been discontinued, Sandvik/Kanthal are making heating element wires from HIPped billets of PM alloys of the FeCrAl variety. These may be considered a very specialised form of stainless steel and volumes are probably in the kt/pa range, while value is high. 

More recently still, we have seen the huge hype around additive manufacturing (AM). In the case of metals this consumes metal powders, and stainless steels have been a significant sector. That said, the powder specifications are still much debated and volumes are very small, and prices amazingly high – around 10 times the levels for MIM, let alone sinter grade powders. This technology is about 40 years behind sintering and 20 years behind MIM in its stage of growth. Given the recent costly takeovers in this field, there are clearly those who are convinced that it has huge growth potential, but the lesson of history is that this growth is likely to take decades to develop. Its impact on the demand for stainless steel powder is likely to be modest in terms of tonnage for quite some time.

The current state of the stainless powder market, which includes at least three different atomising methods and numerous incompatible user specifications, is that global consumption is of the order of 30–40kt/yr, and growth of this figure is not dramatic, even if specific applications, like AM, might show very high growth rates from tiny baselines. Even ignoring the wide range of compositions being made as powder, the largest of which are probably austenitic, ferritic and precipitation hardening grades, the huge number of specifications in terms of particle size, particle shape, oxygen content and inclusion content, means that the market has a very limited number of players, perhaps comprising less than 10 companies, and that there is very little commercial logic in major stainless steel producers getting involved in a sector with volumes some three orders of magnitude smaller than the wrought stainless sector.

 John J Dunkley MA, CEng, FREng, FIMMM, PhD, Chairman at Atomising Systems Ltd, UK

Then – Composite coating gives extra rocket thrust

We reported in January 1993 that the US Strategic Defense Initiative was developing hafnium carbide-tantalum coatings for use in rocket engines that could withstand temperatures of 3,900°C. The coatings were fabricated by chemical vapour deposition and ranged in composition from pure hafnium carbide to pure tantalum carbide, applied in coating thicknesses between 10–380μm.

Now – Aluminium-silumin coatings fused in substrates

Rather than deposit a coating onto a substrate, scientists at Tomsk Polytechnic University (TPU), Russia, have developed a method to fuse wear-resistant coatings formed of aluminium, silumin (an alloy of aluminium and silicon) and titanium nitride to the desired substrate using an intense pulsed electron beam.

‘Now the main challenge is adhesion between coating and substrate,’ said lead researcher, Yuri Ivanov, Professor at the TPU Department of Nanomaterials and Nanotechnologies. ‘If a coating is simply deposited, then it can be easily removed. Foreign research teams are looking for a solution to this issue by forming multi-layer coating. However, multi-layer deposition takes a long time. We offer fusing coating in substrate – this takes microseconds, and adhesion is significantly improved,’ he said. The coating could be used for internal mechanical parts in spacecraft. 

Then – Raman microscope reveals molecular information

GD Pitt and IP Hayward, both from Renishaw, UK, reported the development of a new Raman microscope capable of showing molecular orientation, stress and strain, defects and transformations in polymers and composite materials, ‘[moving] Raman imaging from the laboratory into the industrial environment.’

Now – Raman, rheometry and optics combine

The flowability and microstructure of 'gooey' materials such as gels, molten polymers and biofluids can be correlated using a new three-in-one instrument developed by the National Institute of Standards and Technology (NIST), and Thermo Fisher Scientific, USA.

Integrating a Raman spectrometer, a rotational rheometer and an optical microscope, the new rheo-Raman microscope is designed to take simultaneous measurements to yield a clear picture of how structure and flow behaviour determine macroscopic properties such as strength, hardness and electrical conductivity. 

‘It allows you to trace the evolution of microstructure across a range of temperatures and to do it in one controlled experiment rather that in two or three,’ said NIST materials scientist, Anthony Kotula. One of the first intended applications is as a tool to better understand how polymer crystallisation proceeds during 3D printing.

The Editors of Materials World past

Previous Editors of Materials World reflect on their time
at the helm of the Institute’s member magazine.  

Louise Kittle, Editor from August 2011–June 2014

What was your favourite MW piece to work on?

This is slightly tricky for me as I did very little feature writing in my time as Editor, with five titles to look after. I guess I'd say the CPD content on upcoming stars in the industry (we did a great 35 under 35 piece) was the most inspiring – to see young people doing great things in sectors that are struggling with recruitment and an ageing workforce made me feel very positive for the future.

What do you miss about working on MW?

The passion of members and the committees I worked with to produce the content was really impressive. And of course the views from my desk at 1 Carlton House Terrace across St James' Park to Big Ben. We had a particularly good view of the beach volleyball at the London 2012 Olympics!

Where are you and what are you doing now? 

I'm Editor of Horse&Rider magazine, which is the UK's biggest selling equestrian monthly and has just been awarded Consumer Magazine of the Year, as well as being Editor in Chief of its sister title, PONY.

Melanie Rutherford, Editor from July 2014–April 2015

What was your favourite MW piece to work on?

So many to choose from! I loved working on the timeline feature celebrating the bicentenary of the birth of Sir Henry Bessemer. It was a great article visually as well as factually fascinating. It was an honour to work closely with Bessemer's great great grandson, Paul Bessemer, to put this piece together. 

What do you miss about working on MW?

The fabulous editorial team! I'm proud to see how far my young team has come, especially Simon, who I hired as Staff Writer back in 2014 and has taken the helm of Materials World so well. 

I also miss attending the monthly IMMa lecture and social events, many of which provided great material for mining features in MW. Finally, I miss my annual mini-break up north to attend the ClayTech UK in sunny Stafford for MW’s sister title Clay Technology.

Where are you and what are you doing now? 

I left MW to pursue my dream of becoming a personal trainer (PT). It was a tough decision but the best I ever made, and I knew I was leaving the magazine in very good hands. I now work as a PT at Equinox gym in Kensington, and also privately on a freelance basis.

Katherine Williams, Editor from September 2005–September 2010

What was your favourite MW piece to work on?

Pore it in (see Materials World, February 2006, page 16). The author Gérard Férey, Professor of Chemistry at the Université de Versailles in France, was a delight to work with and at that point I was still fairly new to Materials World and knew nothing about zeolites. I also loved meeting Steve McDanels of NASA to talk about piecing together the materials puzzle created by the Columbia shuttle crash. Working with Jack Harris was a joy too – his ability to take any topic and make it materials-centric was astounding! 

What do you miss about working on MW?

The adrenaline as deadline approaches and the delight of opening the box from the printer. 

Where are you and what are you doing now? 

I still tinker at the edges of Materials World. I have a broader responsibility for our magazines, journals and IMMAGE. If Simon lets me, I still write for MW occasionally.

James Perkins, Editor from May 2015–March 2016

What was your favourite MW piece to work on?

I met a dental researcher from Kings College London, UK on a surf trip to Cornwall and was inspired to look into dental materials for an MW feature. I got a tour of the Kings College labs, and spoke to three different researchers, each with an interesting story to tell. It was a challenging topic, but one that I enjoyed writing about. I had never had a filling, so didn't know what amalgam was until then.

What do you miss about working on MW?

Going to see lectures from charismatic scientists. One that comes to mind is when Sir Harry Bhadeshia talked about graphene at the Royal School of Mines at Imperial College London, UK – it was entertaining, informative and a little controversial. And working with the MW team, of course.

Where are you and what are you doing now? 

I live on the Gold Coast, in Queensland, Australia, and I am Senior Journalist at Business News Australia.

Nuna Staniaszek, Editor from January 1993–October 1999

What was your favourite MW piece to work on?

It’s hard to remember that far back but I remember enjoying putting together the results of a micrograph competition – I always loved beautiful microstructures and found them fascinating.

What do you miss about working on MW?

Being directly in touch with what’s happening in materials – getting to meet and talk to people who are actually doing the research, making discoveries and exploring the potential of materials. I also used to enjoy the satisfaction of having something tangible every month to show for the magazine team’s work.

Where are you and what are you doing now? 

I’m Director of Communications at IOM3, so I still get glimpses of the magazine in the production stage as my team is involved in producing the pages, and I have some input into the content of Institute News produced by Viki Taylor, our Communications Manager. The magazine has gone from strength to strength over the years and it’s still a pleasure to have it land on my desk every month.

Sarah Cleevely, Editor from September 2003–July 2004

What was your favourite MW piece to work on?

We ran a special issue on sports materials including an article on the full body swimming costumes that Michael Phelps wore, which I think have now been banned from competition. I also went to Goodwood to write a feature on a youth engineering project, where youngsters designed their own energy efficient vehicles and then got the opportunity to drive them on the track.

What do you miss about working on MW?

The whole process of putting a magazine together, from commissioning the articles, interviewing people for features, designing the page layout and then seeing the finished product printed each month. I also enjoyed putting the magazine online.

Where are you and what are you doing now? 

I started working as Marketing Manager for Nolan uPVC, UK, a manufacturer and installer of window and door systems in 2008, and eight years on I am still there, doing marketing and advertising for the business two days a week. Since last January the Nolan Charity Fund was started, so I am also the Fundraising and Events Manager for the charity three days a week. I live in Tenby, with my husband Steve, and our three beagles – Sky, Evo and Cooper.