The Secret of Japanese Swords - Science View

The impressive functionality of the Japanese sword, perfected in an elegant form, has led to it being called metal art. They are known to be inflexible. Unbreakable and very sharp throughout history dating back more than a millennium. Countless expert blacksmiths have advanced the craft, and yet a period of This lineage is shrouded in a veil of mystery. The methods used in the 16th century and earlier have been lost. The details of their techniques are now unknown what type of materials were used and under what circumstances researchers have worked to discover the truth behind these

swords

. Japanese

swords

that embody the spirit. and the mastery of its creators in this episode we use

science

to wrap the mystery within the metal Gefu University is here where the

science

behind Japanese swords is being investigated by a devoted researcher Nakia is an associate professor specializing in the study of metal resistance material.

She had previously researched materials for use in devices such as the frame of a car, however, she found a new source of inspiration: a Japanese sword believed to have been made in the 16th century or earlier. The blade is shrouded in mystery. Swords resembling their modern form are believed to have first emerged. Around the 11th century, in the long years that followed, its cutting functionality progressively improved, but in the 17th century, with the birth of the Edo shanet, Japan entered an era of continued peace. Swords were valued less as weapons than as decorations. The swords of previous times.

They came to be called ancient swords and the techniques for their creation were lost to the sands of time. Nakagata has made it his mission to search for these lost methods, which could have caused the methods of creating ancient swords to fade into history displaying a large number of weapons. The Japanese Sword Museum may contain some answers. Sword-making techniques were passed down from master to apprentice. They were shared only among a small number of people and were never committed to writing. These are the Lost Traditions that Nakata pursues. He believes the metal's specific qualities are key.

For the solution that one of the trades of Japanese swords is that a single blade contains different points with different qualities such as hardness and durability, Nakata believes that revealing these qualities could lead us back to traditional methods. In this program we closely examine two procedures that could play a role in Realizing the swords, the first is bent, forging the second cooling, we witnessed the processes in a Japanese sword forge. This is the manufacturer MTA masayoshi. He showed us what T Haan's Japanese swords are made of. Japan's unique steel shape made of iron sand, it is smoother and more. flexible than the iron ore normally used for Western swords, which gives Japanese blades their distinctive properties so folded forging is a process developed exclusively for Japanese swords.

A tah Haan dough is first made by heating it to over 1000°C and then hit with a hammer and then a slit is cut. in half and bent in half, then the newly bent steel is hammered again and then bent. This repetition can continue dozens of times. The work continues for three days repeating the process. Forged folded imbus the strength for which Japanese swords are known, the test of forging. It is marked on the blade. The folding creates countless delicate patterns that ingeniously cover it. Layers only 11,000 millimeters thick are superimposed more than 30,000 times to form complex patterns.

This folded forging process that gives Japanese swords their strength is the same. To give it its beauty after forging the hot steel is quickly cooled with water in the process known as quenching. This crucial step is necessary to give Japanese swords their edge, however, within the reputation of being inflexible, unbreakable and sharply sharp, there lurks a contradiction in maintaining it. To prevent a blade from breaking, durability and flexibility are required, this allows the Force to simply warp it without breaking it, but to prevent it from bending, a blade must be hard. Swords are also brittle when a certain degree of force is applied.

Sword makers can combine the contrasting properties of hardness and flexibility in a single blade the answer lies in the changing properties caused by changes in temperature Mastering the science of steel to reveal the details two cooling methods were compared the first sample was heated to about 830 degrees of the approximate heat at which the cooling is done then immersed in water to cool it quickly after the temperature drops, the metal is secured. Force is applied by adding 1kg weights one by one, when a total of 4kg are added, the metal finally breaks with the other sample, the metal gradually cools. at room temperature for 15 minutes, the metal temperature drops once again.

This time weights are applied when the weights reach 4 kg, the metal bends but does not break. The only difference between these methods is rapid or gradual cooling. Why might this distinction occur? steel is mainly composed of iron and carbon when it reaches a certain temperature the carbon atoms move between the iron atoms if the steel in this state is cooled quickly the iron atoms contract trapping the carbon between them the metal forms a structure Martin Zite extremely hard when the metal is slowly cooled, the carbon atoms are allowed to escape almost completely, this forms the most durable pearlite structure, the cooling process forms both types of steel at the same time, the cooling is carried out simultaneously, which raises the question of how cooling times can be individually. regulated, the response is an important step taken just before shutting down.

A clay-like substance is being prepared. This is quenching ground made from a mixture that includes clay charcoal and whetstone powder, as the ingredients and their proportions have a direct effect on the quality of the sword. The details are a closely guarded

secret

Once the quenching earth is prepared, it is spread along the length of the sword before the quenching areas where the fine earth is applied harden; In other words, changing the thickness of the ground directly affects the amount of time needed for the metal to cool. The blade with cooling earth applied is placed inside the oven, the entire blade is heated evenly once the temperature has risen enough, it is immersed in water, the sections where the cooling earth is applied are finely cooled quickly while The thicker areas retain their heat by cooling slowly, this is the

secret

.

To make steel that has hard and flexible parts, the sword is complete. The white wave-like marks on the leaf are known as leaf patterns and are created as a result of the cooling of the soil. They come from the technique that has been used for more than 1,000 years to manufacture. It is a strong and aesthetically pleasing blade. The method is largely based on scientific properties. However, the details of the materials and temperatures greatly affect the sword's properties, making the sword-making process in the 16th century and earlier largely a mystery. If these techniques were revived in the modern world, would you like to use them?

Many scientists are trying to discover the secrets of ancient swords. One of them is Associate Professor Tanaka Manako. She explains that sword research has progressed since the early 20th century. century the then cutting-edge utility of the microscope was used to examine cross sections of swords. Differences in heart hardness and impurities were extracted by hand. These data show the composition found in the sword sections. Phosphorus, sulfur and manganese levels clearly reveal the structure. of tamahagane within him Tanaka is currently working on a process to analyze Japanese swords without breaking or damaging them. Neutrons known for their ability to pass through matter can be used in data analysis.

They are expected to reveal qualities of the steel such as crystalline structure and The size condition and internal effect of cooling of these images show a sample analyzed directly before and after cooling. Tanaka sees Japanese swords as a research topic with great scientific appeal, meanwhile, Nakata has made great efforts to decode the process of creating historical swords. In April 2022, he launched a crowdfunding project to begin individual research began. With a preliminary experiment on a modern Japanese sword he measured the hardness across the entire blade these were the results this shows a cross section of the sword with the bottom area being the edge the red sections are the hardest with the blue the sections becoming harder soft The nothing experiment shows that the edge is extremely hard, but the area just a few millimeters from it becomes progressively softer for even deeper analysis.

Several cross sections were removed from these, the strength of the steel was measured. The numbered sections are where samples were taken from this is the actual sample to accurately measure the degree of tension when pulled. It was machine cut into this shape. The sample is pulled vertically examining the deformation of the metal. It was found that the Near The Edge samples would not stretch significantly and were less likely to break when a force threshold was exceeded, as Nakata has concluded that the Variable strength of steel could reveal the ways in which it is bent by forging and quenching. were performed, he plans to carry out this experiment on real ancient swords while his research begins from the smaller samples.

Nakata believes that research can have great importance in the modern era. Japanese swords have achieved a unique evolution over the course of more than a century. millennium its mystery acts as a call to arms for researchers who wish to discover the secrets of the swords.