1. Forming Processes for the Future University of Central Lancashire Faculty of Arts. Humanities and Social Sciences Department of Design Student: Matthew Nin Course/Area: BA (Hons) Ceramics Year/Level: 3 Module Code: DD3000 Module Title: Contextual Studies – Design Futures Ceramic Applications

2. Introduction Since mankind has walked this earth we have consistently managed to make use of our surroundings and materials to our best advantage. We have accomplished many things, some of which could not have been achieved without the discovery of clay. The use of clay as a preferred material in certain applications can be dated back centuries. Every civilisation has discovered clay can be used for various tasks in aiding them however in the past it was more of a craft affair with individual potters and makers. Right up until the early 19th century many of the traditional forming techniques had remained unchanged. These were the fundamental laws of ceramic processing discovered by early settlers in communities around the world. Many of which have remained the same yet the way in which we are applying these rules has changed. Ceramics has a diverse and rich heritage claiming the oldest recorded products created by man. Because of its versatile properties it has been possible to manufacture a wide range of products and applications from the obvious tiles, tableware, sanitary ware and weather resistant garden products to the less apparent, achieved using high spec technical ceramics in medical products and engineering to name a few. Old preconceptions of clay as a material are very different to where we have arrived at today. Clay is seen to be brittle, porous, messy, disobedient and unpredictable. However relatively recent discoveries of forming processes in the 20 th century and the possibility of experimenting with various combinations of aggregates has proven ceramics to be a superior material to all others in its category. In the following document I will explore the past present and future of the new and old forming processes as well as the materials used. I will try to shed light on the future of ceramics as well as where it all began and how it has changed throughout time. What has become of these new technologies? Where next? 1

3. Archaeological evidence surviving from 12,000 years ago during the Incipient Jomon period in what is now Japan suggests that the first functional wares were made by joining hand moulded slabs together. This method was then outdated by smoothing together large coils of clay which were then paddled with the hand or piece of wood. Coiling remains the most geographically widespread traditional technique to this day. It was the process of choice for centuries,however the introduction of the ‘wheel’ meant it was possible to produce pots at a much faster rate than they could be coiled. The process of ‘throwing’ appeared first in China in the 4 th millennium BC and simultaneously in Mesopotamia from where it spread to Egypt by 2400 BC. The wheel had now made it possible to make much more symmetrical forms compared to any other previous technique. It was a big turning point in ceramics as a craft. The wheel made it possible to produce ware much faster allowing an experienced potter to get a superior batch production line going in comparison to that of a coiler. The earliest wheels were large solid discs which were balanced on a central pivot. They were set spinning with the hand or with a stick inserted into a notch near the outer edge of the disk, this method is still used today in Japan and India. It wasn’t until the 20 th century that the wheel was made aware of in South America and it is still rarely found in traditional societies south of the Sahara. Past Processes In order to come to terms with where we have ended up today in the application of modern ceramic materials, we must first go right back to the beginning and see why our ancestors used it and its roll in a growing society. As there was nothing in the beginning, ergonomic growth was decided not only by natural resources and climate, but by primitive agriculture. Hunter-gathering was a very old economy of great importance to ancient people and as communities grew, as did the economy, thus presenting new obstacles to climb in the communal side of life. Eating habits have created a natural progression in the early products of man. The earliest products made from clay were very simple pinch pots. Pinching is simply a method of shaping clay by inserting the thumb into a ball of clay and then lightly pinching it out as you rotate it in your other hand to create a bowl. These were then fired and used to hold food and water. The introduction of containers seemed inevitable as it made sharing out food and other resources easier for the nomadic man and his family. Often it was the women of the village who made the ‘early tableware’. It was a seasonal activity for women in tribal communities as it had to be fitted in between the tasks of the agricultural year – ploughing, sowing, harvesting and the movement of flocks and herds, as well as other daily tasks such as cultivation, food preparation and childcare. In different regions of the world the form of the bowl or containers produced by the local folk may originally have been inspired by the shape of coconuts, seashells or baskets. Spherical forms dominate as these have the most structural integrity. Right: a traditional pivot wheel being used in Tibet to apply decoration. Above: Two ancient pots from the Incipient Jomon period. Right: A thrown and assembled pot by Antonia Salmon. 2

4. Past Processes Clay is used in all sorts of weird and wonderful applications, almost as much in the past as it is today. What’s great about clay is that it’s available to everyone. Throughout history people from all nations have experimented in their own way with what they have dug up themselves. This also makes ceramics unique to each country as every clay has different properties giving different results to one another. People have found all sorts of uses for clay within their communities. From pottery to houses, decoration to insect repellent, body paint and ovens. Kaolin and morphine has been used to treat digestive problems, soothing the pain and lining the stomach. Kaolin is in fact just china clay disguised under a more appetizing title. On the Peruvian Altiplano they use local clay as a potato relish which sounds rather bizarre. Much like birds eating clay pellets for the minerals trapped inside. Throwing was the birth of the male potter, as it was mainly women who made all the wares before using the older techniques. Still very much a craft, ceramics slowed in its advancements in processes and applications. Many great artists have used ceramics as a craft of choice throughout history however we needed to start thinking about more useful applications for clay as a ceramic. Not only that, but with a growing world population, companies were beginning to supply to a much wider audience instead of the small batch production crafts of villages and small towns. The age was moving ever so closer yet still very slowly towards the industrial manufacturing of ceramics. Slip casting made it possible to manufacture thousands of the same product in new exciting shapes which would be identical to one another, opening new avenues for all sorts of products. The first records of making pottery in moulds date back to the Hellenistic Greece and the Roman Empire. A simple, hollow bowl shaped mould was made out of clay, with a design impressed or incised into the sides. This was fired, and then the inside smeared with clay and smoothed on a rotating potters wheel. The form pulled away from the mould as it dried. This process of smearing clay onto the mould was later replaced by pouring a runny mixture of clay and water into the mould to coat the inside (slip). As civilization advanced, plaster of paris moulds replaced clay moulds, and so the technique developed over time into the modern day version we now use. Above: A production line of slip cast and moulded porcelain pieces from the Herend Porcelain Factory in Hungary. Below: Filling the plaster moulds with slip 3 Right: Red- and-green parrots clinging onto the side of their mineral rich clay lick wall in Peru.

5. Present Processes Once the initial shape has been pressed it can be refined by green machining (see above image.). This technique is most commonly applied to pressed parts which are still in a chalky condition (die pressed). Ordinary metalworking machines are used to machine the part in this soft condition as a greater material removal rate is possible compared to post sintering operations such as diamond grinding which also costs a lot more. This process is fast and efficient, because it can use the common metalworking machinery it doesn’t cost as much to produce and the process gives out a higher turnover. This particular process will carry on and the parts will still be fired after machining to increase its durability. However some ceramic parts used for small components that aren’t necessarily on the forefront of any products use (getting wear and tear) wont need sintering to be efficient. These are known as machineable ceramics. Die pressing is by far the most widely used shaping technique for advanced ceramics. Granular powder is compacted into a die and thus compressing the material together under intense pressure. Above: Diagram of a Die Pressing process A variety of materials we use for all sorts of different applications have influenced each other throughout a millennia. Like the fibres in basket making, clay can be manipulated in its plastic state to make the coils of a pot in a similar manor. Whereas rolled into slabs it can be assembled like wood or metal. The same is happening still, with new processes being opened up to the possibility of use with a diverse range of materials to its more common. Tape casting is a relatively new ceramic forming process, it involves pouring the slip onto a moving carrier belt, it then passes under a stationary “doctor blade” to adjust the thickness and is then air dried to form the “tape”. This can then be peeled off the carrier belt, cut into rectangular shapes, and processed further. The layers can be ultra thin thanks to the polymer binder added to the slip to give it strength. This allows up to 100 tape layers to be stacked on top of one another. Alternating with conductive metal powder layers making multilayer capacitors and sensors etc. The polymer that is added to the slip burns out in the sintering process. More than a billion of these capacitors are now being manufactured daily with the advance in technology of mobile phones and automobiles in the past 20 years. Above and right: A tape casting carrier belt after thinning. Right: the tape can be cut and manipulated or processed further. 4

6. Present Processes The continuous strides forward in science and technology lead to ever increasing demands on materials. Ceramics have significant advantages characterised by their outstanding physical, chemical, mechanical, thermal and/or electrical properties. This opens the door to a wide variety of application possibilities when other materials fail to perform, while maintaining great versatility and freedom in the design of components. The inherent hardness of ceramic materials mean that manufacturing complex shaped ceramic components by standard machining processes can be expensive. Other manufacturing processes such as dry pressing or extrusion limit part complexity. There is an apparent move away from the energy inefficient and wasteful practice of machining off material, towards more efficient net-shape fabrication. Much of which can be done using CAD and the data is then simply fed into a processor and into the machine to manufacture. This in turn has allowed production engineers and product designers to improve productivity, lower manufacturing costs and improve product performance. The forming process I am referring to is called ‘Injection moulding’ which is mostly known for moulding intricate plastic shapes in all kinds of products and toys for example but has now widened its horizons with the possibility of using all kinds of new material combinations. The process for ceramic compound injection moulding is comparable to plastics. It is simply the heating up of a mix until it has a sufficiently low viscosity to allow it to flow into any given mould when pressure is applied. It offers an economic solution for delivering repeatable, ultra high precision ceramic components. Allowing engineers great versatility and freedom in the design of advanced ceramic components. Designs previously rejected as too difficult or expensive to manufacture using other production techniques are made commercially possible. Features such as multi-shaped blind holes, screw threads, surface profiles, perpendicular holes, undercuts and intricate cavities are all now possible using ceramic injection moulding technology. Whilst having the attributes of good electrical and thermal insulation, machineable ceramics can be machined using conventional metal working tools and do not require diamond grinding. This means that the turnaround of a component can be relatively fast however there is a disadvantage to the other ceramic forming processes as these machineable ceramics tend to be relatively weak and brittle compared with other ceramics. It also costs a lot more for a greater volume of parts when machining as it takes more material to produce the parts. There is also more waste in comparison to the injection moulding process. Below is a graph comparing the cost of manufacture for a few processes. 5 Above: A ceramic compound Injection moulded kettle.

7. Present Processes The next process up from injection moulding is purely for advanced ceramics. Typically used for cylindrical components, iso-static pressing is the compaction of ceramic powder in a flexible mould. Technical ceramics are rigid materials that can resist much higher temperatures than high- temperature insulating materials or textiles. The choice of the ceramic compound will vary depending on the specific application (steatite, alumina, zirconia, etc.). Every combination has its advantages In different areas. Today, heat-resistant materials play an important role in semiconductors which are the core of our computer world. This world of computers is growing every day with new products becoming smaller and more compact for the user such as the ipod collection for example and much more memory taxing touch screen phones and hand held computers. Thus meaning the components inside are much more tightly packed and smaller than that of a personal computer at home but still need to have excellent electrical insulation, excellent high frequency properties as well as heat, pressure and arc resistance. Ceramics can be manufactured to have all of these properties using a multitude of processes making it truly the material of the 21 st century. MICALEX is a company on the cutting edge of heat-resistance material technology by minimizing the generation of gas caused by the corrosion of glass material at a temperature of 700°C. With its excellent accuracy and stability, it is behind the scenes supporting the microchip industry for much bigger computers in the realms of science and medical assisting computers which need a lot more processing power to work efficiently. 6 Technology has jumped forward in great leaps and bounds over the last few decades to arrive at a position were high volume ceramic components can be made using injection moulding techniques. Injection moulding of ceramic components has several major benefits over more traditional manufacturing techniques such as die pressing and green machining. Excluding the obvious; that it is a good technique for very high volume parts, injection moulding has also proved to be an excellent technique for making components such as turbo charger rotors and thrust bearings which would be too expensive if the parts were machined. Low pressure injection moulding (LPIM) provides an excellent option for producing ceramic components using low cost tools in comparison to high pressure moulding techniques.

8. Present Processes Machining with carbide can be difficult, as carbide is more brittle than other tool materials, making it susceptible to chipping and breaking. To offset this, many manufacturers sell carbide inserts and matching insert holders. With this setup, the small carbide insert is held in place by a larger tool made of a less brittle material (usually steel). This gives the benefit of using carbide without the high cost of making the entire tool out of carbide and so most modern face mills use carbide inserts, as well as some lathe tools. An example of the benefits of upgrading machinery tool parts with new high spec. ceramic based materials is a wire cutting company in America (OEM). Their specialized wire cutting machine used a tool-steel funnel to position a steel wire for cutting. In a short period of time, the rubbing of the wire damaged the funnel which then caused damage to the wire. This required shutting down the machine, re-arranging the inlet funnel to a smooth spot and re-starting the machine. The resulting downtime, wire loss from abrasions, and replacement of the inlet funnels became costly and difficult to manage. Insaco engineers, working with the OEM wire cutting machine manufacturer, Crescent Design, proposed changing the funnel to a hot isostatic pressed zirconia material significantly improving wear quality when compared to metals and even most other technical ceramics. After two years of use there was no noticeable wear in the inlet funnel, no wasted material run, and virtually no downtime from the zirconia replacement. Right –Zirconia wire cutting funnel part designed to reduce damage from friction off the wire running through. When forming technical ceramic materials from dry powders prepared for processing, the method of forming into the shape required depends upon the method of material preparation and size and shape of the part to be formed. Materials prepared for dry powder forming are most commonly formed by "dry" pressing in mechanical or hydraulic powder compacting presses selected for the necessary force and powder fill depth. Carbide cutting surfaces are often useful when machining through materials such as carbon steel or stainless steel, as well as in situations where other tools would wear away, such as high-quantity production runs. Sometimes, carbide will leave a better finish on the part, and allow faster machining. Carbide tools can also withstand higher temperatures than standard high speed steel tools. The material is usually tungsten-carbide cobalt, also called "cemented carbide", a metal matrix composite where tungsten carbide particles are the aggregate and metallic cobalt serves as the matrix. The naturally ductile cobalt metal serves to offset the characteristic brittle behaviour of the tungsten carbide ceramic, thus raising its toughness and durability. 7

9. Present Processes Traditional applications include consumer products like dinnerware or ovenware and construction products like tiles. We have already established that most of these applications have been in use for many years and therefore markets are mature with single digit growth. Now we can manufacture a multitude of products using advanced applications to take advantage of specific mechanical/electrical/optical/biomedical/chemical properties of ceramic materials. They have entered the scene over the last several decades or so. The markets for some of these applications can have double digit growth because of the intensive and complex forming process transforming the material into its future individual application. These are applications such as drill pieces and tools within machinery, new textile materials for wire and armour, car brakes, clutches, windscreens that protect you from all UV rays and porcelain teeth to name a few. Kyocera are a Japanese company that for the past 10 years have been making the worlds first ceramic knives which are stronger, sharper and easier to clean than conventional knives. Because they are ceramic, they don’t rust and the toughened zirconia blade it is made from makes it only second to diamond in strength. This was all made possible thanks to the forming process known as hot isostatic pressing. 8 ceramic powder is moulded into blade "blanks" with special high pressure presses. Special binders in the powder allow the blanks to retain their shape before sintering (or firing), which takes several days at extremely high temperatures (in excess of 1000 C). The knife blanks are then ground and polished on a diamond wheel to form an edge before the handle is attached. Over the last twenty years there has been a considerable increase in the use of ceramic materials for implant devices. With an excellent combination of strength and toughness together with bio-inert properties and low wear rates, Y-TZP is now displacing alumina in applications such as femoral heads for total hip replacements. The zirconia heads display double the strength of comparable alumina heads and consequently the diameter of the femoral head can be reduced to < 26mm, leading to a reduction in patient trauma during the hip replacement operation. Ceramic bearings are used big and small, from skateboard and roller-skate wheel bearings to larger industrial sized bearings and machine parts. Above and below: Different heat proof material made from ceramic fibres. Used in fireproof jackets, lining in kilns and the american nascar racing drivers wear an assortment of advanced ceramic clothing and components to keep them as cool as possible inside the cockpit.

10. Future Potential Advanced ceramics are playing a critical role in the development of highly-efficient and cost-effective new technologies for space travel. Morgan Technical Ceramics’ division in Erlangen, Germany has been working with a European space development program for a number of years to support its research of ion propulsion systems. A lightweight alternative to traditional chemical propulsion, ion engines have the potential to push spacecraft up to ten times faster with the same fuel consumption, thereby significantly decreasing vehicle size and increasing travel distance. Ion propulsion technology, which uses electricity to charge heavy gas atoms that accelerate from the spacecraft at high velocity and push it forwards, traditionally incorporated quartz discharge vessels. Quartz has now been replaced by the ceramic oxide called alumina because of the need for a material with the same dielectric properties but with higher structural stability. Alumina is easier to fabricate and offers good thermal shock resistance, ensuring that the chamber can withstand the extremes of temperature that occur during plasma ignition. It is also lighter, which reduces the costs associated with each launch. Japan are currently testing a train that is for the Central Japan Railway Company ("JR Central") which has successfully utilised high temperature superconductor (HTS) wire in a prototype electromagnetic coil designed for use as the lifting component in JR Central's magnetically levitated ("maglev") train system. The core of the bearings consists of a magnetic rail and superconducting bulks, cooled to a temperature of -196 °C. During the cooling process, the magnetic field of the rail will be written in the superconductors, which are positioned at a set distance from the magnetic rail. This enables them to retain a set horizontal position in relation to the rail. JR Central and Japan's Railway Technical Research Institute's (RTRI) current maglev train system, which today must rely on low temperature superconductor (LTS) electromagnets, recently set a world speed record of 581 kilometres per hour (360 miles per hour) for the highest speed attained by a manned superconducting magnetically levitating train while "flying" about 10 centimetres (4 inches) above its "track." Above: a small superconductor in action. It is in a constant state of suspension until the base warms up. Bottom middle and right: NASA's Deep Space-1 spacecraft was the first to use ion engines for propulsion [source: SPACE.com] As u can see they are a lot smaller than chemical propulsion engines. Right: An ion propulsion system successful controlled test. SPACE.com 9

11. Future Potential As I see it, the future of ceramic forming is bright. There are infinite possibilities in which these new forming techniques can be used to get the most out of the material as well as there being scope to carry on researching new compound combinations. I predict that in the not so distant future, space travel for the masses will be made available. With tourist trips around the world in the outer atmosphere and hotels in space, it will create a massive market for space travel manufacture of a wide variety of products and transport. Transport in particular will benefit most from the ceramic forming techniques being used today to create safe, reliable crafts and stations armoured with high spec ceramic plating to withstand the highest of temperatures whilst providing a hard outer shell to stop any shrapnel that may happen to hit it. It will also allows us to make better looking craft, just like the carbon fibre cars of today but with ceramic and carbon compound materials being formed under extreme hot isostatic pressing then assembled to create an aesthetically pleasing body for small family sized crafts. The process with zirconia makes its surfaces ultra smooth so the aerodynamics of design could be made efficiently whilst maintaining its body shell strength. Even the insides of these new forms of transport would rely on a lot of ceramic components within their computer systems such as semiconductors and electronic equipment to withstand heat from ever growing powerful processors because of the memory taxing new software and bigger new forms of data storage. There could well be a big step forward in the research of superconductors in the next 50 years making “hover cars” possible, running on magnetic highways where paths can be pre-determined and the driver can sit back and relax. Much like in the sci-fi movies of today such as ‘i-robot’ directed by Alex Proyas. Not only automobiles but absolutely anything could be given the superconductor technology for charging purposes or to use power instead of wires, your television could be floating off a powered floor tiling The military are increasingly taking more interest in the properties that these new high spec materials have to offer. Already today they are using Silicon nitride (a non- oxide ceramic) which is used in radomes for missiles in the latest air defence systems. The latest body armour in service inside Iraq and Afghanistan is made from ceramic plates because of the superior properties the material has. It makes the armour light weight, the ability to withstand extremely high temperatures, hardness, resistance to wear and corrosion, low friction, and special electrical properties. These all offer major advantages over conventional materials Most of the aircraft armour systems are fully integrated with ceramic components and protection. These include ceramic armour seats, components, and panel systems found in the Apache, Chinook and the well know Blackhawk helicopters. Right centre: Virgins concept for the first space transport vehicle available to the wealthy public. 10

12. Future Potential Steel will always be widely used in many building and product applications because it is less expensive to use however there is always a lot of waste in the manufacturing process of steel whereas with ceramics there is very little waste because of the precision of each mould and the amount of material used. However, with the invention of new transport and faster more efficient manufacturing techniques for a greater production line in all areas needed with an ever increasing population around the globe, there will be a need for materials that can withstand the test of time. The high temperatures and precision cutting needed in the mass production of new products and applications would certainly require the high spec properties of materials such as zirconia, alumina, silicon carbide, and zirconia toughened alumina to mention a few. Already as alleged these new materials are widely used in the industry today for machining other materials to reduce wear time and improve performance. It seems to me that mankind has done a full loop in the discovery and application of materials and inventions. Today we are very much a carbon footprint aware society and the saving of the environment we live in has become top priority. This means that businesses will have a greater chance of success if they can incorporate this into their production, making less waste and producing products that wont be harmful to the atmosphere - bad news for the plastics industry which fell by the end of the 70’s anyway relying on oil but great news for ceramicists and researchers alike. There is much need for some new (or revamped) materials to use in industry. Even steam power has now made a return with prospects looking into the sky for the first time since the 1930’s and steam powered cars producing fewer pollutants. Even nanotechnology and space travel could benefit in the future from steam power. “No matter how old the technology, there are always new and better ways to make that technology work for humankind” Lynne Angel (team coordinator for BSCC’ steam powered concept car). This statement goes with all technology we have created in the past and within ceramics you can see the steady improvement of older forming processes being looked at once more and improved for the higher performance materials being created and higher demanding technology to be used in. 11

13. Bibliography Websites http://www.specialtyblades.com http://www.molas.org.uk/projects/ELG/history.asp http://www.metrokitchen.com/kyocera/ http://www.bokerknives.net/ http://www.bbc.co.uk/wiltshire/features/fire_found.shtml http://www.guardian.co.uk/science/2007/feb/13/uknews.archaeology http://www.ornl.gov/info/ornlreview/rev28-4/text/gelcast.htm http://www.dynacer.com http://books.google.com/books?id=oWRXvrgFhqUC&pg=PA167&lpg=PA167&dq=modern+ceramic+forming+techniques&so urce=web&ots=Germ23YmY1&sig=FFFjFQpvS2oINWLQ-23wHAPEqZg#PPA169,M1http://books.google.com/books?id=oWRXvrgFhqUC&pg=PA167&lpg=PA167&dq=modern+ceramic+forming+techniques&so urce=web&ots=Germ23YmY1&sig=FFFjFQpvS2oINWLQ-23wHAPEqZg#PPA169,M1 http://www.superiortechceramics.com/ http://www.deltec.fr http://www.globalspec.com http://www.macstourport.com http://www.xylonceramics.com http://en.wikipedia.org/wiki/High temperature_superconductivityhttp://www.superconductors.org/Type2.htmhttp://en.wikipedia.org/wiki/High temperature_superconductivityhttp://www.superconductors.org/Type2.htm http://www.suptech.com/tech_faq.htm http://www.superlife.info/en/index.html Books Handbuilt Ceramics: Pinching, Coiling, Extruding, Moulding, Slip Casting... By Kathy Triplett Ceramic Processing and Sintering, Second Edition (Materials Engineering) (Hardcover) by Mohamed N. Rahaman Ceramics, Materials for inspirational design – by Chris Lefteri, forward by Karim Rashid Institute of ceramics- textbook series – the effect of heat on ceramics – by W.F.Ford Ceramics, A world guide to traditional techniques – by Bryan Sentence Oxide ceramics, Physical chemistry and technology – by Eugene Ryshkewitch 12