Some misunderstandings about of Titanium Alloy and Titanium frame
Misled 1: Titanium alloy is light, lighter than aluminum, similar to carbon fiber. I don't have the exact data of the carbon fiber, let's put it aside. Let's see three kinds of metal materials commonly used on bicycles: steel, aluminum, and titanium. Three materials of sample volume, which can be obtained from these three numerical calculations, are about 57.4% of the weight of the steel and about 34.4% of the weight of the steel. So aluminum is the lightest, and it is simple to say that the same volume of aluminum is 40% lighter than titanium alloy and 65% lighter than steel. At the same time, the other words that often appear on the Internet will be punctured. Titanium is half the weight of the steel. To be precise, it should be more than 57%.
Misled 2: Titanium is a rare metal, so it's more expensive. I don't know much about this. The titanium element has no exaggeration to say, "Take a handful of soil on the ground, and carry out the analysis of the next element, and a lot of titanium elements can be found." Titanium is expensive, not because of the scarcity, but is due to the difficulty of smelting and post-processing.
Misled 3: The more thick the welding of the titanium alloy frame, the more reliable the welding spot is. The welding of the metal is to use the high heat energy to make the contact point between the metal, the instant reach and even exceed the melting point, let the weldments join the principle of the moment to work. See the table below to see the respective melting points of the three metals. As can be said, the larger the welding area, the greater the welding heat demand, the greater the heat accumulation, the arrangement of the metal molecules, the change in the arrangement of the metal molecules, and the internal stress variation of the metal. The stress cannot be eliminated, and it is likely to cause hardening and embrittlement of the weld surface. It appears to be a bit of a deep, simple point that the thermal effect and heat treatment of the titanium metal and other metals are completely different, high melting point and completely oxygen-free, and the heat energy storage on the welding port must be reduced as much as possible. So that the generation of metal stress can be reduced. Therefore, when welding, the welding port is better fused, and the large-area welding should not be pursued. Practice has proved that the more complex the welding, the more the more reinforced titanium frame, the greater the probability of problems. Of course this is not absolute, some companies have advanced titanium alloy product heat-treatment equipment, which can reduce this risk through special heat treatment technology. It is important to be vigilant here. The welding scar (the surface fish scale bump after welding) can not eliminate the stress in the metal, polish the welding position of the titanium alloy, especially the titanium alloy, but instead may reduce the welding strength, this must be noted, It's better to buy a titanium frame and don't buy a bond.
Misleading the four:6-4 ti frame is the best titanium frame. Many people use the titanium frame in general to compare with the frame of other materials, and there is love and hate. It's a man's condition. In fact, it is necessary to carry out the classification of the titanium frame, as is the steel frame, some of which is made of carbon steel, some of which are manganese and steel, and the price is also different. The good steel frame is also ten thousand yuan, this is not a fresh topic. The aluminum frame also has the same price difference between the two frames due to the different materials of the aluminum alloy, the frame manufacturer, the vehicle, the manufacturing process, the surface treatment process, and the like. As with the titanium frame, there are hundreds of titanium frames that have been passed from my hand in the past few years. The price difference is still big. So it's not like a material-like frame, that's the same quality. It must be a matter of matter to be separated. For some time, it is said that the frame of the 6-4 titanium alloy is the best titanium frame. I've been asking about this, too. And then, it's not the same thing. Let's first say what's going on in the 6-4 titanium alloy. According to the provisions of GB/ T 3602.1 -2007, the alloy grade TC4 is the titanium alloy of the nominal chemical composition of Ti-6Al-4V, which is known as 6-4 titanium. In the alloy, the aluminum (Al) component accounts for 5.5 to 6.5 percent, the carbon dioxide (V) component accounts for 3.5 to 4.5 percent, and the balance after the two components is removed by 100 percent is the impurities of titanium and other elements. Two metals of this proportion are added to the titanium, so that the titanium alloy has better mechanical properties, and the application range of the alloy is expanding. The greatest advantage is that the hardness is improved. A bicycle can be made in such a way that it is actually very hard in hardness. In fact, however, there is no country in the world to be able to produce a large amount of 6-4 titanium alloy seamless tube, and the seamless tube is required to have more advanced equipment and technology than large steel mills. There is no doubt that this has limited the manufacture of a 6-4 seamless tube. This is also the reason for almost a few 6-4 seamless pipe materials in the world. (Some of the pipes, such as the five-way and the head pipe, can be made into a tubular shape with 6-4 titanium alloy bar, which is not a pipe). Then why would someone say that his frame was a 6-4 titanium alloy? And why in the 6-4 titanium alloy frame of Europe and the United States for a time, several manufacturers have stopped production again? The reason is simple, and the tube forming process is pipe-welded (with a seam). How many of the so-called 6-4 titanium pipe frames crack, what the manufacturer has happened, I don't open it. All right, all of you know. The aluminum is not elastic, the addition ratio is high, more like the road feeling of the aluminum frame, which is also proved by the practice. On the other hand, the 3-2.5 titanium alloy was developed about 30 years ago and was the best material for the bicycle frame. This has been proved by numerous practices in the past and in the future. Misleading 5: The titanium alloy is relatively soft and is not wear-resistant. This is a delusion, and this is not to be taken out, and it's not worth it to those who have no practical experience. A more absurd statement appeared in No.03,2011, when the author described the titanium-alloy handle as a "to grab the mud from the hand", which was not too much to talk about. It's like a fool to be a reader. If you take 3-2.5 titanium alloy pipe + aluminum alloy pipe + steel pipe with the same wall thickness in three sections, cut the steel saw blade for metal cutting to see what is called hardness. Because of the same blade, cutting the other two metals will be relatively easy, but when the wheel comes to you to cut off the titanium pipe, you will find how the saw teeth are so slippery! About the wear or not, I've only two examples,1) a piece of titanium alloy disc, I choose a heavy off-road car as the front wheel brake, specially tested for about half a year, the order sheet for the brake is G3 oil, the front plate of the front plate is worn soon, A new and a few months later, it was found that it was much more worn than the back wheel. And the disc itself has no trace of wear. This is sufficient to ensure that the wear-resistance of the titanium alloy is better than that of the steel. If you don't believe, look at the drill bits that are drilled in the metal, why the titanium-plated drill bit (to exclude some of the homemade fake products) is so useful and life-long. 2) It's the titanium shaft chain I used. It is better than the steel chain, and the durable is visible to the eyes and the body feels. Misled 6: The imported titanium material or the frame must be better than the domestic ones, and the domestic products are garbage. There will be more and more people to refute the claim through practice. I'm sure! All the hearsay will fall out after the practice and get the final result. Many of my old customers have done the corresponding test. The feedback was a relief to me and the business. Don't let the consistent way of thinking become a bad habit of keeping your bad habits. That's the truth. I'm cool for those who stubbornly think that their country is not good. Just ignore it. You can do it. That's why foreign titanium is so good. Why is the important titanium alloy raw material imported from China's largest titanium enterprise by Boeing, Airbus, Rolls-Royce and so on? Why not the 60-year-old Russia of the study of titanium is not Germany that has advanced technology, but China, why?