Too much choice can be paralysing.
Just think if you went to a shop to pick up some glue and there were thousands of different types to choose from, all with slightly different properties.
That is the choice that you face when having to select a material in the modern world. There is a plethora of options.
This has its advantages in some respects, as it means you’re more likely to get an exact match to the properties you need. But, it makes finding that perfect material much more difficult.
A brief history of materials
Prior to the 19th and 20th centuries, there wasn’t a great deal of choice when it came to materials. You were pretty much limited to the naturally occurring ones; wood, base metals, clay, etc.
Then came the industrial revolution and the spread of academia, and suddenly more and more materials were being invented and developed. By the start of the 20th century, most universities that offered engineering courses had a metallurgy department which led to metal alloys and other discoveries.
Then came the age of the polymers which propelled different types of plastic to become widely used materials.
In the 21st century, the choice is staggering. There are tens of thousands of metals alone. This has made material selection a very complex undertaking, unless you get some expert assistance.
The consequences of poor material selection
The wrong material choice can be costly, or even catastrophic.
In fact, one of the most well-known disasters of the 20th century could have been caused by poor material choice.
Rivets recovered from the hull of the Titanic, which sank in 1912, have been analysed by experts and they believe that they may have contributed to the disaster. When the ship collided with an iceberg, the hull may have ripped apart, not only due to the force of the impact but the weakness of the rivets.
At the time of manufacture, the standard rivet used in shipbuilding was made from No. 4 iron, known as “best-best”. The 48 rivets collected from the Titanic were made from No. 3 iron, simply known as “best”.
This poor choice of material may have been responsible for the sinking of the ‘unsinkable ship’ and the loss of 1503 lives.
There are plenty of other examples of poor material selection that has caused damage or loss of life, such as this example of a sprinkler that failed to discharge due to the use of copper pipe, causing over $1,000,000 worth of damage.
How to select the right material
When designing a product, selecting the right material is crucial. But the decision involves many different interlinked factors, including function, design, manufacturing and cost.
Material selection alone is no easy task with such a wide range of choice, as mentioned earlier.
A popular tool when assessing materials are Ashby charts (see example right), which compare different materials of certain types on a scatter graph. So, if the designer needed a lightweight, strong material, the aim would be to get a material with high strength and low density (and often at the lowest price possible).
But as more materials have been invented, different industries have come up with their own methods for selecting materials. Some still rely on using dozens of charts. Others have come up with industry-specific software.
Increasingly, designers and product developers are turning to the internet to select their materials.
Matmatch offers a huge searchable database of materials that can be filtered for a wide range of properties, including elastic modulus and density.
Another handy feature of the Matmatch database is that it allows application tags to be attached to materials, showing which industries or applications have successfully used a given material. These tags are searchable, so if you wanted to find an ideal material for the automotive industry for example, you could select this as a filter in the search bar.
Also, one of the main benefits of using charts was that you could compare different materials in one place. Matmatch allows you to compare material properties side by side, making your selection much easier.
Material selection in the 21st Century isn’t a simple matter. There are tens of thousands of metals available and hundreds of polymers and ceramics, with more and more advanced materials being developed every year, such as graphene and tethonite.
The easiest way to get the best match for your requirements is to use a searchable database such as Matmatch , which allows you to filter and compare dozens of different properties and even search by application.