Looking at the flying sword that had turned into waste again, Zhou Yu thought about it, although the experience would improve faster by refining the flying sword as an experiment, the formation diagram was too complicated, and the movements of his two-handed knot technique were too rusty, so it was inevitable that there would be mistakes.

He decided to practice the tricks by himself first, and after practicing the tricks one by one, he would then punch them into the flying sword, which would save a lot of time and avoid wasting materials.

So, Zhou Yu began to face the air, constantly practicing the formation technique, according to the information transmitted from the radio, re-refining the Wind and Thunder Sword, not just to build a formation, but to fuse several formations with each other, including the formation that stimulates the power of the wind and thunder, the formation that increases the power of the flying sword, and the formation that zooms in and out.

In this way, after a week, he continued to practice every day, and tried again with the flying sword from time to time, so that he became more and more proficient in the action of depicting the formation diagram, and of course, he also practiced a lot of materials, four tons of materials, and now there is only one ton left.

Moreover, there was another thing that happened during the period, that is, he finished depicting two formations, and when he carved three more, the flying sword exploded directly, and after analysis, he understood that this was because the materials used in the flying sword could not support the power of the formation.

Just like he carved a higher-level Spirit Gathering Array on ordinary jade, jade would definitely not be able to withstand it, and he now understood why the refining weapon should be integrated into other materials, it was because with the help of the different characteristics of the material, the refined artifact could withstand more formation power.

This is also the reason why modern metal alloys are tougher than a single metal, and then he fused two different types of powder steel together, and added Huanglongyu at the same time, and sure enough, the toughness increased, and it was able to withstand two and a half formations.

Understanding this truth, Zhou Yu did not directly buy other metals, but first injected individual formations into the flying swords, and waited until these formation techniques were proficient, and then considered adding other metals to refine the flying swords.

In the continuous experiment, he also found a poem that is of great help to his spirit and eyesight, after writing, the effect of the poem can help him concentrate more energy, and his eyes will become special, directly see through the composition of the formation inside the flying sword, and his reaction ability has become faster, as if standing in a higher position, to watch his own actions to depict the formation.

After understanding the role of this poem, he also deliberately took out the Wind Thunder Sword and studied the construction and fusion of the array diagram inside, which made his confidence more sufficient.

However, before refining the Wind Thunder Sword again, he still had to go through a final experiment to ensure that each formation could be perfectly integrated into the Flying Sword, and now the materials he had could not support the integration of these formations together, so he had to buy some metals again to synthesize and refine.

Through these flying swords to test the formation diagram, if the wind and thunder sword is abolished, then he estimates that he can only let the radio turn on the frequency again, rob Ren Tianba or Wu Dali, and let them take another flying sword.

After studying the metal elements for a while, suddenly, the sound of a radio appeared in his head, pointing out several metals he wanted to buy, as well as the temperature and technique of refining and fusing them.

It seems that the radio predecessor still can't help but take the initiative, he was just going to ask, his purpose is to enter the world of Xianxia, and at the same time, the strength of the radio will also increase.

Zhou Yu looked at these metals, which basically increased the toughness and strength of steel, including the well-known rare earth elements.

Looking at these metal elements, he smiled helplessly, it seems that he still has to buy them through Qi Jinxuan, not to mention other metals, just rare earths, which cannot be bought from the Internet.

After deciding, Zhou Yu called Qi Jinxuan directly, and explained the types of metal elements to be purchased on the phone.

Qi Jinxuan glared, and directly let out a national scolding, ", there are rare earths, you are not playing with knives, you are building missiles." "Others play with a knife, at most use a powder steel, plus some other metals, to form the effect of Damascus, this Zhou Yu plays a knife, and even needs rare earths and so many metal elements.

"Cough, Brother Qi, since you play with knives, you have to be different, I'm still experimenting to see which kind of metal is added to it, and the best knife is made, you just wait and see, when I succeed, the knife made must be extraordinary, and it is not a problem to sharpen iron like clay." Zhou Yu coughed twice and used the flickering Dafa again.

Not to mention adding these elements, even if the kitchen knife he now uses powder steel and yellow dragon jade to make can sharpen iron like clay, and even the bones of spirit beasts can be easily cut, and iron and the like can't be stopped at all.

"Poof, you kid is playing with knives and playing crazy, I'm really going to spend a lot of effort on research. Qi Jinxuan couldn't help laughing, adding a rare earth knife, he really didn't dare to imagine it.

"Brother Qi, if you give up halfway, your money for four tons of steel will be wasted, and I won't give the money. Zhou Yu half-jokingly threatened.

"I've convinced you kid, at least two knives, what elements do you want, I'll see if I can get it for you." Qi Jinxuan shook his head helplessly and asked.

Rare earth has 17 kinds of metal elements, each element has different functions, some of them are very small in rare earth ores, the process of separation and extraction is more complex and difficult, and some elements he may not be able to get.

So, Zhou Yu told Qi Jinxuan about the two elements he needed, if he brought the rare earth ore over, he could refine it with Haoran Fire himself, and there might have been some problems in the past, but since he studied that poem, he could directly see the metal elements in the ore through his eyes.

"I don't know if I can get these two elements yet, I'll ask later, if it's okay, I'll get you a kilogram of each, and how much of the other metals. Qi Jinxuan said with some uncertainty, he knew the seventeen elements in rare earths, but he was not sure about the specific rarity.

"Hehe, thank you, Brother Qi, just make a few kilograms of each other metal, I'll do the experiment." Zhou Yu said with a smile, these metals are auxiliary materials, to help steel become tougher, powder steel still has to be made as the main material.

"You kid take advantage of your youth, have fun, remember, succeed at least two knives, sharpen iron like clay. Qi Jinxuan scolded with a smile, thinking that Zhou Yu might be young and playful, otherwise it would be impossible to suddenly study the knife, and he would be so whimsical to add rare earths.

"Don't worry, Brother Qi, sharpen iron like clay, blow hair and break hair, Tong Su is not bullied. Zhou Yu assured with confidence.

Qi Jinxuan couldn't help but smile, "Okay, then I'll wait, let's do this first, counting rare earths, I can ship them to you in two or three days at most." ”

(End of chapter)