Tony Stark motioned for Qin Li to follow him as he walked to another laboratory. While walking, he said, "You probably won't get it just by hearing about it. Let me demonstrate and explain at the same time." He reached a workstation and began using high heat to melt steel into a bright red liquid. He then poured it into a mold, and once it began to solidify, he immediately placed the glowing red iron sword into the lower-grade hardener. Instead of the sizzling sound he expected, the hardener slowly evaporated, and impurities floated away.
Once the floating particles stopped appearing, Tony Stark used a mechanical arm to pull the iron sword out for polishing. The originally silver-white iron sword had turned a dull grayish white.
Qin Li, confused, asked, "So it only changed color? What else does it do?"
Tony Stark gave him a look of disbelief and shook his head. "The color changed, but the uniformity and almost perfect integration of the steel is what matters. You think it's just a color change?"
Qin Li shrugged. "Well, what else should I expect? Not everyone can be a genius like you."
Tony Stark slapped his forehead, realizing he had overestimated Qin Li's understanding. He thought Qin Li, being the one to provide such extraordinary materials, would have some knowledge. He sighed and explained, "This lower-grade hardener doesn't react with steel in its normal state. However, when steel reaches a certain temperature, it undergoes a vigorous neutralization reaction, eliminating impurities and even replenishing the steel as if it had a mind of its own. It's incredible."
Qin Li, feeling as though he were listening to an old monk chanting, didn't understand. He asked directly, "So, what does it do?"
Tony Stark started to explain some data but then realized Qin Li wouldn't understand. He waved it off, saying, "Just watch. I have a regular steel sword here that wasn't enhanced by your lower-grade hardener, made from the same batch of steel."
Tony then used another mechanical arm to grab a silver-white sword and continued, "This one is forged. It should be much stronger than the cast sword you saw earlier. You'll understand why I'm so impressed with your hardener after you see it."
"Wait, what's the difference between forged and cast?" Qin Li asked, suddenly curious.
"Ugh, damn it. How do you not know this?" Tony Stark exclaimed in frustration.
"Hey, I'm not a blacksmith. What do I know about it?" Qin Li replied nonchalantly.
"Alright, I'll keep it simple. Forging involves hammering the metal, while casting is like what you just saw. Got it?" Tony said impatiently.
"I see, I get it now. What's next?" Qin Li said, pretending to understand, then raised his fist in realization.
Tony didn't respond but immediately started clashing the two swords together. The sound of metal clashing filled the room as the silver-white sword cracked open. Then Tony used the mechanical arm with the grayish-white sword to strike again. With a crisp sound, the silver-white sword was cleaved in two.
"See that? This steel sword made with your material is far stronger than a regular forged one. The most amazing part is that the lower-grade hardener can be added during forging without lowering the temperature of the steel, which defies the laws of science," Tony said, amazed.
Qin Li, uninterested, said, "Why don't you just tell me it makes regular steel stronger? Why all the theatrics?"
Tony Stark was defeated by Qin Li's indifference but couldn't help it. After all, only Qin Li had this miraculous lower-grade hardener. Then, Tony suddenly seemed to remember something and asked urgently, "Li, since you call this a lower-grade hardener, does that mean there are middle-grade and high-grade ones? Can I see them?"
Qin Li waved him off, saying, "We'll talk about that later. Didn't you say you figured out how to use the carbon crystal? What about that?"
Tony, realizing that Qin Li was changing the subject, gave up asking about the other materials. He continued, "The carbon crystal is even easier to use than the lower-grade hardener. Just grind it into powder and add it to steel to increase its hardness. The more you add, the stronger it becomes. I've tried different ratios, and the best mix is 7:3, with steel to carbon crystal. Any more and it becomes too brittle. But a sword with this ratio is even stronger than one forged with your lower-grade hardener. You should take a look."
Tony then picked up the silver-white broken sword with a mechanical arm and placed it aside. He grabbed a sword with faint purple streaks running through it. The purple glowed subtly in the silver's reflection, like stars in the daylight. Tony struck the sword made with the lower-grade hardener against the new one, and the grayish-white sword broke with a crisp sound.
Qin Li, seeing this, was impressed. "So this material can make regular steel that strong? What about the crystal and the magical rock? Those must be even more amazing."
Tony's eyes widened. "Exactly! You're using these materials to make your Mark 3?"
"Yes, my friend, don't tell me you're out of them?" Tony said nervously, realizing how rare these materials were and fearing that Qin Li didn't have enough left.
Qin Li smiled, "It's not a problem. I'll give you some when we go to your warehouse later."
"Great! Let's go," Tony said, relieved. He had planned to use these materials for his new armor but was worried about running out.
"Alright, let's head to the warehouse," Qin Li said. "We'll drop off the stuff and take the night off. Tony, look at those dark circles under your eyes. You're looking worse."
"Okay, okay, you're more annoying than Pepper," Tony said, pretending to be annoyed but feeling a warmth in his heart. No one had said something like that to him since his parents passed away.
Qin Li shrugged. "I'm just looking out for you. You can stay here in your basement, but I'm taking the materials."
"Fine, fine! Let's go now!" Tony sighed, realizing he was caught, but he was glad to have those incredible materials for his suit.