Materials science 2: Ceramics – properties, production, and differences
When you think of ceramics, you usually think of your grandma’s china. Cookware such as the roasting dish for the Sunday roast or the measuring cup for measuring the right amount of milk that goes into the cake or dishes like your favorite cup you fill with coffee in the morning. But, ceramics is so much more. Apart from being widely found in the kitchen, it is also used in such areas as medical, electrical and systems engineering, in the chemical and the textile industry, in electronics, in toolmaking and in mechanical engineering. Finally, let us not forget the vast field of jewelry. And this is exactly where we come into play: Because we offer you the option of personalizing your very own piece of ceramic jewelry with ease and in the comfort of your own home. "Pearl with Soul" is the name of this product line. All you need for this project is a strand of hair or less than one gram of the ashes of a deceased loved one plus a few minutes of time. You will then proceed by using the mini laboratory we provide to create from ceramics a unique pearl that will remind you of your dearest every day. But, what exactly is ceramics? Since when has this material been part of human existence? Also, what exciting facts are there about ceramics production and what properties does this material have? Quite a few! We will thus dedicate the blog post below to this topic.
A brief history of ceramics
It has never been established precisely when we humans first came across this versatile material and discovered its incredible potential. The fact is that pieces of ancient pottery have been found in various regions of the world. Among the oldest ceramics findings are clay vessels from Siberia and China. We can therefore assume that the discovery of ceramics as a material for making receptacles and artifacts was made independently on various continents. There is one thing we can safely say: The manufacture of ceramics ranks among the oldest cultural achievements of mankind. Pottery was initially made exclusively in “open-pit fires” before humans built kilns much later. The cultures of the Early Stone Age were particularly partial to this material as it allowed them to cook their food and store their supplies. An interesting side note: The rising tendency to use ceramics in the kitchen and for storage also increasingly led humans to form resident populations, the reason being that the solid receptacles were ideal for cooking, but not so much for transport due to their heavy weight and fragile nature. More lightweight materials progressively supplanted ceramics - especially in kitchenware made at the end of the 20th century. However, there has been a trend of late to return to such values as sustainability and longevity. It seems that ceramics is back in style again. Meanwhile, the age of electrical ceramics began to dawn around 1850 when the multipurpose material was manufactured around electrical insulators for the first time. By the way, the term “ceramics” originated in Ancient Greek. It traces back to the word “keramos”, which identified clay minerals and anything made from these minerals. The trade itself was referred to as “keramike” – a term which later shifted meaning to denote ceramic products. Today, ceramics is an umbrella term for a multitude of inorganic, non-metal materials with silicate ceramics (e.g. porcelain), oxide ceramics (e.g. aluminum oxide) and non-oxide ceramics (e.g. silicon nitride) being the most common groups. An area of tremendous importance is the already mentioned field of technical ceramics, also referred to as high-performance ceramics. Products for medical and technical applications, for instance, require a highly specific grain size of the base material.
Ceramics: About production
Let us therefore look in more detail at how ceramics are manufactured: The base material is clay / loam. This material is mixed with water, adding the ability to shape the finely granulated and powdery particles perfectly. The main components of ceramics thus boil down to quartz, granite, metal oxides, loam and sand. Once it has been given the desired shape, the product needs to be dried and then baked to gain more stability. The rule to follow: The harder you wish the material to be, the higher the temperatures need to be. This rule is now summarized in the term “sintering”: Temperatures starting at around 1,000 degrees give ceramics such typical properties as hardness, strength and thermal conductivity.
Temperature defines the properties of ceramics
Temperature plays a key role in the production process as it helps bring out a variety of characteristics. This ability to change its properties is what turns ceramics into such an interesting and versatile material – while other materials, such as metal, are unalterable. This is also the reason why there is no such thing as one type of ceramics. Rather, there is a wide range of “ceramics” that needs to be grouped into categories – for example, into decorative and technical ceramics. Add to this the expansive range of surface finishing options – from polishing or laser machining to the application of no-firing and firing colors to glazes. While hard, decorative ceramics such as vases or sculptures are also highly fragile. But, a baked-in glaze can make them waterproof or add ornamentation. By contrast, technical ceramics is distinguished by a host of desirable properties that vary with their field of application: It can be hard, wear-resistant and resistant to cold, heat and shape deformation. Or, it can be electronically insulating, resistant to corrosion, and water-repellent or offer high or low thermal conductivity. No matter if you require kitchen countertops, heating elements, tooth fillings or electrical insulators for high-voltage power lines or spark plugs – ceramic material is multi-functional.
Ceramics in the world of jewelry
Ceramic material has long established itself as a staple in the world of jewelry. In this area it has distinguished itself with its exceptional skin compatibility, its hardness - and the resulting scratch resistance - and its durability. The material is an excellent choice for creating unique beads, pendants, rings or other accessories that can even be worn by allergy patients and will not lose one iota of their charm and singularity for many years to come. What is more, jewelry made from ceramics is easy to care for and will not tarnish or oxidize. Another advantage is that ceramic jewelry can be customized with individual color designs and even allows for engravings or stone settings. This is why we have made this multifunctional material the material of choice for our “Pearls with Soul”. By the way: Each of these pearls is in a class by itself as it is made by hand and thus boasts its own uniquely rounded shape.