How are ceramic knives made?
The technical process for creating zirconium blades is as follows: obtaining alloyed zirconium oxide powders, preparing press compositions and pressing, firing at high temperatures (1350C+, in some cases up to 1700C), hot isostatic pressing at high temperatures and pressure.
The process of making ceramic knives is quite labor-intensive. To obtain a ceramic blade, zirconium dioxide powder is first pressed under a pressure of 300 tons per square centimeter, then subjected to heat treatment at temperatures of 1600-2000 degrees Celsius in special furnaces for a long time (from two to six days). In this case, sintering of zirconium dioxide crystals occurs and the process of forming blanks occurs. The longer the product is kept in the oven, the stronger it becomes. Depending on the characteristics of the technological process, black or white ceramics are obtained. Black ceramics are made by adding a special black dye and keeping the pieces in ovens for a longer time, as a result of which they become stronger. The quality of ceramic knives varies greatly from each other, since it greatly depends on the technological capabilities of the manufacturer, and on compliance with a complex technological process.
How to use a stone knife today?
From time immemorial, in order to survive, people were forced to use different tools, devices and, of course, weapons.
Most people know that knives are usually made from iron, steel and other metals. However, it is important to remember that throughout a huge period of history, our ancestors used stone knives. Scientists consider the stone knife to be one of the most ancient types of weapons on our planet. As proof of this, you can see many old engravings, excavations and drawings, where a knife carved from stone is sure to be found.
The best raw material for such a knife has always been volcanic glass - obsidian - due to its strength and ability to be sharpened to incredible sharpness.
What are the features of a stone knife?
To begin with, it is important to note that a stone knife is quite heavy.
Although it does not allow you to strike as fast as many metal knives, almost any hit with a stone knife will be fatal.
This is a knife for which there are no barriers. Regardless of the amount of clothing and protection, it is impossible for a person to resist such a blow.
However, looking at a stone knife, many will probably think that it is something too primitive, and this thing has long been a thing of the past. But that's not true. The stone knife served many functions, including being used in battle during the Spanish Wars of Conquest. Then, over time, many of the technical elements of working with this type of weapon formed other systems in the American continents among the entire Spanish-speaking population, as well as in South Africa .
It's no secret that South Africa's criminal tradition, with its gangs of numbers, is considered one of the most dangerous systems in the world. Of course, time passed, the world changed, and the knives changed. In South Africa, lighter knives began to be used, which transformed the working technique of the South African criminal from a counterattack system to an attack one. However, the basic technical elements remained unchanged. As an example, we can compare the blows of the ancient Mayans and Aztecs during sacrifices with some modern blows in the South African criminal tradition.
Today, in the CIS countries, little is known about the Spanish stone knife, which cannot be said about Spain itself, in particular about the Canary Islands, where the Teide volcano is located, from the obsidian of which stone knives are made to this day. A large-scale study in this area in 2020 was conducted by the head of the research institute “Research of world military traditions and forensic studies of the use of weapons,” academician of the UAS Oleg Viktorovich Maltsev. During scientific expeditions to Spain, the Expeditionary Force visited a huge number of Spanish libraries and archives. According to the scientist, this study was not easy:
“Such work requires special analysis methods. The research should be carried out not by one person, but by a whole group of scientists. In addition, it is necessary to thoroughly understand the martial arts, and then be able to compare the data obtained, not to mention the fact that most of the research was conducted in Spanish.”
What benefits does training with a stone knife give?
As a result of the work carried out, a group of Ukrainian scientists managed to completely restore the ancient history of the stone knife, as well as the technique of working with it and its connection with more modern military systems.
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By the way, at the beginning of 2020, the school hosted the first cultural and historical seminar in the CIS (today it is available in video format) on Spanish techniques for working with knives such as Canary, stone and Navaja.
The technique of working with a stone knife is the second stage of training in working with bladed weapons after learning to work with a Canarian knife.
“On the one hand, we learn to work with a stone knife. It is heavy and no one uses it anymore. However, we will need this at the third level, when we learn to work with Navaja. In addition, given that the stone knife is made in the image of a human fist, working with it also prepares us for fist fighting and gives us the ability to disarm the enemy. Thus, owning a stone knife makes it possible to learn how to conduct hand-to-hand combat, as well as use improvised means if you are left alone with an armed enemy .” - says UAS academician and professor at Destreza Oleg Maltsev.
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Pros and cons of a ceramic knife
The properties of zirconium ceramics significantly depend on the technology of its production, starting from the purity of the original zirconium powder, the alloying system, the granulometry of the powders, sintering modes, etc.
In mechanical properties, zirconium ceramics are significantly inferior to the most common steels, in particular, in bending strength by approximately two times, and in impact toughness by several times. This greatly limits the versatility of ceramic knives. Due to their fragility, most manufacturers advise against using these knives for meat with bones, frozen foods, working on hard surfaces (glass, ceramics), etc. It should be noted that in terms of corrosion resistance and inertness to products, ceramics have unique properties that are superior to any steel.
DIY wooden knives
Wooden knife Wood
can be used as a cutting tool, especially in camping conditions. To make a wooden knife with your own hands, you need to use chips and flakes of coniferous branches that have a sharp cutting edge or other durable and high-quality wood. The process of making a knife from wood with your own hands is simpler than a steel one: you need to prepare a sketch you like on paper, which is transferred to a wooden canvas. Wooden knives are usually made monolithic. After this, the handle and blade are given the desired shape using a chisel or file, and the blade is sharpened. The finished product is varnished or fired.
Another option for making a wooden knife is to make it from medium-thick plywood. Similar to the work described above, first a sketch is made. Then you need to prepare the three components of the blade: the blade and two parts of the handle, consisting of a round holder and a support plate. The blade is sharpened and the handle is processed with a file and sandpaper to remove any rough edges.
Sharpening a ceramic knife
A ceramic knife, due to the fragility of the cutting edge, requires fairly large sharpening angles. On average, it is recommended to sharpen it at a full angle within 30-40 degrees. Sharp angles of 20 degrees or less are contraindicated for such knives, since the fragility of the cutting edge at such a sharpening angle becomes very large. Sharpening ceramic knives is also complicated by the fact that the process does not create a burr and angle control must be maintained using special devices, primarily an electronic angle meter. Thus, manual sharpening of ceramic knives, without the use of sharpeners, requires extraordinary, virtuoso skills from the sharpener.
Not all abrasive materials can cope with sharpening a ceramic knife. Budget stones made of silicon carbide and aluminum oxide do not cope with ceramic knives. The quality of the grinding powder and bond plays a key role here. American Boride CS-HD sharpening stones perform very well in sharpening ceramic knives. The grit of the stone should not be very coarse; in particular, Boride CS-HD for sharpening ceramics should be started with a stone of 320 grit, since a coarser abrasive will lead to the formation of cracks on the cutting edge. Obviously, the reason for this result is the very high quality of the silicon carbide powder and ceramic porcelain binder used in the products of this American manufacturer.
Also, good results when sharpening such knives are shown by diamond plates with a galvanic bond and diamond bars with an organic bond. CBN bars are slightly less active in sharpening them, as they remove the zirconium layer not as quickly as diamonds. But all these abrasives are suitable for such sharpening and allow you to get a good cutting edge.
What do you think about sharpening ceramic knives, write in the comments.
History of development from stone to modern
Man first began to use a knife immediately after he stopped walking on all fours and began to get food with improvised means. The tools that people began to use for hunting and farming were fragments of bones or stones. The first ones were much easier to make, due to the fragility of the animal’s bones, but such products dulled unusually quickly, and not all components of the skeleton were suitable for the role of a sharp instrument.
To make a knife from stone, primitive man had to put in a lot of effort. However, the laboriousness of the process was compensated by its relative strength and the ability to sharpen the edge of a stone blade. Another advantage of a stone knife over a bone one was the durability of the tool. Bone weapons were fragile and often broke during hunting, so this type gradually passed into economic use and construction.
At the time of human mastery of metalworking, edged weapons began to be made from bronze and copper. They were significantly superior to stone samples in terms of durability. The blades were made from a single piece of metal. Swords, daggers, and knives of those times became indispensable weapons for the soldiers of the Roman Empire, with the help of which troops conquered new territories.
The Iron Age is the age of experimentation and new technologies. Knives acquired different shapes and lengths; at this time, sickle-shaped and wave-shaped blades were invented. In Rus' at that time, edged weapons were included in the attributes of the nobility and merchants. The Vikings used wood to make sword hilts so that the steel, frozen in the cold, would not burn the hand.
In the Middle Ages, people began to use steel - an alloy of iron and carbon - in the production of swords. These times were considered bloody; history knows many large-scale wars and battles. As a result, the emphasis in forges was not on quality, but on quantity. And in comparison with ancient times, the characteristics of the samples of edged weapons of the Middle Ages were much inferior to the ancient prototypes.
Although historians cite the example of the daggers of medieval Arabs. Some of the daggers of Arab sheikhs that have survived to this day have retained their cutting properties, despite the passing of centuries.
During the Renaissance, the experience of blacksmiths, passed down from generation to generation, together with new technologies of that time, resulted in steel cutting products of quite high quality. But just at this time, firearms began to be used in battles, and interest in blades began to gradually fade away.
During the Industrial Revolution, the production of bladed weapons became widespread, moving from handicraft to factory production.
In factories, the manufacturability of the process reduces costs, which means that the product becomes cheaper and is already available to almost everyone. Soon, folding knives and world-famous centers for their production appeared - Russian Zlatoust, English Sheffield, German Solingen and Swedish Eksilstun.
