Since the historical periods of the Stone Age, Bronze Age, and Iron Age, the development of materials has helped expand the limits of human endeavor and achievement. In the 21st century, demands from such industries as aerospace and automotive are pushing the frontiers of material properties to more extreme levels.
It is human nature to always look forward to what we wish was possible. The automobile industry is a prime example of this. When Ford released a wish list of materials for future vehicles, some possibly life-saving materials were on that list.Professor Pim van der Jagt, executive technical leader at Ford’s Research and Advanced Engineering, listed items such as: a new type of steel that is three times stronger than current steel; plastic foam that can stabilize structures during accidents; and nano-filler composites that radically reduce weight while increasing strength. (Source: http://articles.sae.org/12297/)
In the modern age, the aerospace industry is also looking ahead to tougher, lighter, and more heat-resistant materials that would lessen emissions, cut fuel costs, and enable higher speeds. So far, in the aviation industry, composites have been the go-to material. According to Dr. Eleanor Merson, a composite research specialist, “Thirty years ago, five to six percent of an aircraft was made up of composites; now, a commercial plane, such as the Dreamliner, is made up of about 50% composite material.”
Although only one-fifth the weight of steel, carbon fiber composites are stronger. The Dreamliner, for example, has carbon fiber composites in its wings, tail, doors, fuselage and interiors, which makes it a lighter plane. When it comes to aircrafts, every pound counts. Experts estimate that reducing the weight of a commercial aircraft by 2.2 pounds (one kilogram) can lower the cost of operating it by around 2,200 to 3,300 dollars per year.
A Lamborghini Packed with Composites
Composite materials are increasingly being used in cars, wind turbine blades and other products. For example, BMW’s electric i3 is made largely of composites. BMW says the lighter weight helps the vehicle travel as much as 100 miles on a single charge. Lamborghini’s fierce-looking Veneno Roadster is packed with weight-reducing composite parts that enable an acceleration of 0 to 62 miles/hour in 2.9 seconds. Composites are now cheaper to produce, and more companies are making them, but the production of fine-grade composites still requires high temperatures, extremely clean environments and a labor-intensive process. Machining these fine-grade composites is even more of a challenge.
“Cutting, and especially drilling, in composites is a major challenge,” says Merson, who researches composites for Sandvik Coromant. “An aircraft has tens of thousands of holes in it, and the material is very abrasive; carbon fibers quickly wear out the drills.”
In the future, it is probable that composites will be further strengthened by fibers that have been developed at the nanoscale level. It is also expected that scientists will be able to create nearly perfect solutions at an atomic level. Specialists at the German chemical company Altana AG say that tiny carbon nanotubes can be made 400 times stronger than steel or aluminum and 20 times stronger than conventional carbon fibers.
Graphene in Smartphones
Materials such as graphene and quasicrystals, whose discoverers were awarded Nobel Prizes, hold even greater promise for being tough materials and may completely revolutionize industrial design. Widespread industrial applications, however, are not expected for a long time.
Last year, a Chinese company incorporated grains of graphene in its cell phones to improve conductivity. Flakes of quasicrystals have been molded into frying pans and metal surgical instruments to increase their durability. While no major industrial breakthroughs are imminent, heavy investments are currently being made on graphene research. Graphene is 200 times stronger than steel and the thinnest material on earth (1 million times thinner than a human hair). At the same time, researchers at companies and universities are focusing on improving known materials and techniques.
Lightweight aluminum alloys have now replaced high-strength steel in bumper systems, crash ring components and intrusion beams. In aircraft engines, super-hard alloys that are resistant to extreme temperatures can help improve energy conversion and reduce fuel costs.
Coatings Harder than Steel
Physical Vapor Deposition (PVD) and Chemical Vapor Deposition (CVD) are processes for coating objects with an extremely thin but hard and heat-resistant film. The techniques started to be widely used in the 1980s and are still being used for mechanical, optical and electronic devices.
Sandvik Coromant uses these methods to harden the surface of its inserts. The core of the insert is made of cemented carbide consisting mainly of tungsten carbide and cobalt.
“Add a two- to 10-micrometer layer of PVD, and the insert’s life span increases by a factor of 100,” says Dr. Mats Ahlgren, an expert on material physics and head of the PVD Department at Sandvik Coromant. “Not only can customers use the inserts for a much longer time, they can also increase their productivity by working with the inserts at much higher speeds and feeds.”
Their current research focuses on making the coating even tougher to meet the demand for durable materials.
“In recent years, we have developed our ability to control the process of making new coatings,” says Ahlgren. “We can see the structure in microscopes, virtually down to an atomic level, which helps us analyze new solutions before going live.”
In 2013, Sandvik Coromant patented its CVD coating Inveio™. With crystals made to point in a uniform direction, Inveio was a leap forward in durability and hardness.
With the use of tougher materials, there is not as much of a need to use a huge mass of sturdy components in a single structure. Designers are becoming highly selective in choosing materials for different parts of an automobile or aircraft. Some machine parts don’t need to be that strong. This is the philosophy of Ian Scoley, former head of Industrial Design at Airbus, where he focused on cabin design. Currently the head of Industrial Design at C&D Zodiac, Scoley says he draws inspiration from bird bones. “They are strong where they need to be, but they are light and open where they need flexibility.”
Mind-boggling Recycling
While aircraft and cars are using less energy and are producing less exhaust with the help of new materials and design, recyclability is becoming increasingly important. Many composites, for instance, are made with adhesive binders that are difficult to separate and reuse, but recent aluminum alloys for the auto industry are created with future recycling in mind.
In fact, recyclability has become a driving force in automobile manufacturing. European governments require all cars to be built in such a way that 85% of their materials can be reused. “Automotive companies are evaluating every part of the car in order to meet that requirement,” says Arjen Bongard, a Germany-based auto industry analyst.
The recyclability challenge is triggering imaginative solutions. Ford has started using wheat straw and soy products in its interior design and researching coconut husks, carrots, and corn-based plastics for materials. The company’s vision is to produce interiors that are 100% biodegradable.
“Finding alternative materials is an important path, as is the need to create cost-efficient substitution and recycling processes,” says Dr. Anna Hultin Stigenberg, who is the principal R&D expert at Sandvik Coromant. Stigenberg, until recently, chaired the international steering committee Knowledge and Innovation Community for raw materials, an initiative that brings together more than 100 companies and research facilities to promote the development of sustainable material development.
At an Atomic Level
But why settle for materials that already exist? People are developing the capability to create entirely new materials—materials with specific properties.
“We are getting much better at designing new materials at an atomic level with the help of modern microscopes and computer calculations,” says Hultin Stigenberg.
Since the Iron Age ended around 550 B.C.E., no specific material has defined a period in human history. Many academics say we are living in the Plastic Age, but in the future, our epoch may well be labeled as the Age of New Materials and its effects on human development may be much greater than we can now imagine.
