"Hehehehe...... Get up, get up, you don't have to be polite, I'm just going to take a look around......" Bi Maokang smiled and helped the three of them up. Pen ~ fun ~ pavilion www.biquge.info

After the three of them stood up, they stood respectfully to the side, waiting for Bi Maokang to speak.

Bi Maokang looked at the three craftsmen, and said with a smile: "Guohua, let me introduce these three masters to you." As he spoke, he pointed to the three of them and introduced Zhao Guohua in turn: "This is Master Du Decai, this is Master Wei Sanxi, and this is Master Yang Hong." ”

"I have seen three masters in Xia Zhao Guohua." Zhao Guohua bowed respectfully. In later generations, the person who developed this research and development is an expert-level weapons engineer, and he wants to enjoy ****** special allowance, and it is completely appropriate and necessary to give a big gift to such three people, and it is also a respect for talents.

"Childe is polite, the villains are just a few lowly craftsmen, and it is not worth being a childe to do this great gift." The three of them hurriedly arched their hands and said. The three thought that Zhao Guohua was Bi Maokang's nephew.

After introducing the three of them, Bi Maokang said: "Guohua, you follow the three masters over, take a look at the whole process of making the fire gun one by one, if you have any ideas, come and tell the old man, the old man will take a break here." ”

Hearing Bi Maokang's words, the three craftsmen looked at each other, and then took Zhao Guohua to the workshop.

There was a "clanging" inside, hundreds of people were busy inside, and Zhao Guohua carefully watched the process of craftsmen making firecrackers. I saw that some people were responsible for beating iron ingots into iron rods, some people were responsible for beating iron rods into large and small iron sheets, and some were responsible for rolling iron pieces into cylindrical tubes, and the large and small pipes fit properly.

The three of them each led a hundred and ten craftsmen to patiently make the fire guns. After looking at it for a while, Zhao Guohua asked politely: "Master Du, Master Wei, Master Yang, I want to ask, why do you want to do this, this method is slow and laborious, why don't you use the casting method to make the pipe?" ”

"I've seen the casting method, but it's used to make the barrel of the cardinal cannon, and it's used to make a thin pipe like the gun? Will this work? Wei Sanxi listened and hurriedly explained.

Glancing at Zhao Guohua, Du Decai also asked with interest: "Can the son be more specific?" ”

Yang Hong also came up and said: "At first glance, the son is a person who has a university question, and it is a blessing for us to be able to get the guidance of the son." ”

Seeing that the three of them sincerely looked like they were seeking advice, Zhao Guohua said: "I have lived overseas for a few years, and I have seen the method of making pipes overseas......

"Ahh Last time, the adults asked us to find someone to imitate the handcuffs, which Childe brought back from overseas? ......" Wei Sanxi asked in surprise.

Zhao Guohua smiled and nodded.

"Hurry, hurry... Kowtow, kowtow, please advise the child......" As they spoke, the three of them knelt down and kowtowed.

Seeing this, Zhao Guohua hurriedly grabbed the three of them and said, "Masters, you don't need to be like this, you don't need to be like this...... Otherwise, I'm leaving......" After saying that, he looked at the three of them pretending to be angry.

"Okay, okay, don't knock, don't knock......" the three of them said, and hurriedly stood up. Seeing that Zhao Guohua did not accept kowtowing, the three of them no longer insisted.

"Good! That's right! Zhao Guohua said with a smile.

Looking at the three craftsmen, Zhao Guohua said: "Just now I saw that the three masters were very laborious to make the pipe, and then I suddenly remembered the casting method I had seen overseas, so I said it, of course, it is unknown whether that method can be used in my Daming, after all, the situation in the two places is different." ”

In order to be afraid that he would be laughed at if he couldn't make iron pipes by the casting method, Zhao Guohua gave these three people a preventive injection in advance.

"It's okay! Childe, you say, the casting method can't make iron pipes, and the villains won't blame you. Wei Sanxi said.

Du Decai and Yang Hong also said in unison: "That's it!" It is! I won't blame Childe. ”

Hearing what the three of them said, Zhao Guohua smiled and said: "That kind of casting method is called wax mold precision casting, also known as lost wax casting or investment casting. ”

"Wax mold precision casting? Listening to this name, it seems to be made of wax, but wax is so soft and easy to melt, how can it be made into molds?" Wei Sanxi asked thoughtfully.

Zhao Guohua looked at Wei Sanxi, then at Du Decai and Yang Hong, and seeing that the two of them were also confused, he smiled and said, "If you understand as soon as you hear it, you are not craftsmen in the Ming Dynasty." ”

After a pause, he continued, "The specific casting method is to first make a model of the casting to be made of wax, and weld the model to the gate rod with the same material, make a module (when the casting is large, it can be a single group), dip the surface of the module with refractory paint, and then sprinkle refractory sand, dipping slurry and sand to repeat several times to make the sand layer thick enough, and after it is dry and solidified, heat the module to take out the wax material from the gate to form an empty shell. The empty shell is roasted to make a solid mold shell, and the metal liquid is poured through the gate, and after condensation, it becomes a metal casting. ”

Wax mold precision casting originated in the Bronze Age in China and has a history of more than 2,000 years. Now it has been widely used in various industries, and it has many advantages: it can manufacture castings with complex shapes, and can manufacture small-hole thin-walled parts; Suitable for a wide range of metals and alloys; High manufacturing precision.

"Wonderful! Great! Childe said that this method is so wonderful, once we wait for the success of the test, the speed of the iron control will be more than ten times that of the current one. After listening to what Zhao Guohua said, Wei Sanxi said ecstatically. He is the most skilled of the three, so he naturally understands the benefits of this 'wax pattern precision casting method'.

Du Decai and Yang Honghe are not stupid, and after listening to this method, they also feel that the wax mold precision casting method has the possibility of being realized in Daming.

The three of them discussed, Wei Sanxi went to report to Bi Maokang, Bi Maokang listened, thought carefully for a while, and also felt the ingenuity of this method, so he went to tell Wang Gui, the ambassador of the Ordnance Bureau, about it.

Wang Gui asked Bi Maokang, and when he heard Bi Maokang say that this method was possible, Wang Gui was also very happy, at least it would be much easier to complete the tasks assigned by the Ministry of Industry in the future.

In order to get this method out as soon as possible, Wang Gui went to the jewelry store outside to find more than a dozen jewelry makers with the best skills.

Looking at these trembling jewelers standing in front of him, Bi Maokang smiled kindly and said: "Don't be afraid, I'm Bi Maokang, the right waiter of the Nanjing household, and I have something to make for you to make today......

After listening to his words, the jewelry shopkeepers relieved their hearts, Master Bi's reputation is very good in Nanjing, he is upright, and he is kind to people, everyone knows that Lord Bi is a good official and will not harm them.

A jeweler boldly asked, "Master Bi, I wonder what you want to do with the little people?" Please show the adults, and the little ones will be able to act well. ”

"Oh, that's it, come on, bring it up." Bi Maokang said loudly.

With his shout, several craftsmen came up with a few hollow iron pipes of swarthy length and length of feet, and then placed them on the table.

Glancing at these pipes suspiciously, the jeweler said, "Could it be that the adults want us to make this kind of pipe?" ”

"That's right! You are right, you want to make this kind of pipe, but the method is different, you need to make a thin pipe with wax according to the inner diameter of the pipe, and then use wax to make a thick pipe according to the outer diameter of the pipe, and finally put together to fit the iron pipe in. After that, I compared how to install the pipe.

"Oh, isn't this asking us to be Lafan?" Another jeweler said loudly.

In ancient times, the mold was called Fan, and the mold for making money was called Qian Fan.

"That's right! You're right, this official just wants you to be a fan, do a good job, the old man will be rewarded, and if you are sloppy, the old man will never spare it. Whoever does the best will be rewarded with a hundred taels of silver. But you can only do it in the Ordnance Bureau, during this time, everyone will be wronged and live in the Ordnance Bureau. Bi Maokang said non-negotiable.

"We do! We do! "The jewellers took the iron pipes and went down in a hurry.

Seeing this, Bi Maokang and Zhao Guohua looked at each other and smiled.

Wax mold precision casting is not something that can be completed in a day or two, Zhao Guohua had no choice but to stay temporarily, and instruct the jewelers in the Ordnance Bureau every day to make wax patterns according to the thickness of the barrel.

Making wax patterns sounds easy, but in fact it is not the case, he needs to accurately measure the size of the tube, and it is also these jewelers who make jewelry that have the ability to do so.

After several days of exploration and experimentation, the jewelers finally made a wax mold that was exactly the same size as the barrel. Zhao Guohua also commanded the craftsmen to coat the surface of the wax mold with the mud made of refractory mud, and then sprinkled with refractory mud powder, and then coated with a layer of mud after drying, and then sprinkled with refractory mud powder, and then coated and then sprinkled with powder after drying.

Several times in a row, it finally reached a certain thickness, and this step is called "sand". After the casting sand on the surface of the wax model was completely dry, Zhao Guohua instructed the craftsmen to boil the sand-stained wax mold in water

After the wax is boiled, a sand shell is finally left, and this step is called "boiling wax"

"Guohua, this is what Lamo is made of?" Bi Maokang asked curiously as he looked at the heavy clay shell made of refractory mud in his hand.

The craftsmen are also looking at the results of their own time and whispering.

Nodding, Zhao Guohua said: "Uncle, this is made of wax, but it has to be roasted to strengthen its hardness before it can be used." ”

Wang Gui, the ambassador of the Ordnance Bureau, also took the mud shell and looked at it again and again with great interest, and after reading it, he said with a smile:

"Childe's method is really ingenious, once it succeeds, it will be a great merit for the craftsmen, I wish Childe success in advance." After saying that, he carefully took a few clay shells and roasted them on the fire.