In the practical application of carbon fiber materials in the aerospace field, the application of carbon fiber blades in aeroengines encountered many problems. In the end, how did engineers solve the shortcomings of carbon fiber and make it finally applicable to aeroengines?
This is what we are going to talk about today
Titanium-carbon integration technology
Carbon fiber has some inherent disadvantages
Some shortcomings of carbon fiber, such as the ability to withstand high temperatures is not strong, such as easy to deform, etc., so the use of carbon fiber blades in other aircraft engine parts is limited, but used in the position of fan blades, because the temperature is low, Low pressure can avoid the disadvantages mentioned above.
But these two shortcomings are not all the shortcomings of carbon fiber (yes, although carbon fiber has many advantages, but the disadvantages are not one or two). In addition to being resistant to high temperatures and easily deformed, carbon fiber also has problems of being resistant to shock and prone to vibration.
Many people who have bought carbon fiber bikes have known about the problem of impatience, that is, as long as the carbon fiber frame is hit by something, it is prone to "wounds", and these wounds are almost irreparable unless the entire The parts are replaced.
The fan of the aero engine is the front-end component of the engine. When it hits a bird, it is common for anything to be sucked into the engine when it hits the ground. In addition, the carbon fiber blade itself is complicated to manufacture and the price is very high. One blade at a time is afraid that no company can afford it.
Carbon fiber blades are prone to vibration. In essence, carbon fiber blades are caused by low stiffness and large blade size. Therefore, carbon fiber blades in engines are easily affected by external influences. These vibrations will not only have a certain impact on the blade itself, but more importantly, it will cause damage to other parts, so it has to be prevented.
Carbon fiber fan blade tips: titanium and carbon in one
In order to find a way to prevent the carbon fiber fan blades from being injured and prevent the blades from vibrating, the engineers thought of a method. This is called titanium-carbon integration. By adding a full set of titanium alloy edging to the carbon fiber blades, the "soft" carbon fiber The material is used with a "hard" titanium alloy material.
Simply put, the carbon fiber fan blades reinforced with epoxy resin will be further covered with titanium alloy edges (wrapped on the three edges of the leading edge, trailing edge, and outer edge). The titanium alloy has higher rigidity and can also resist the outer Impact, so that eventually the use of carbon fiber in fan blades becomes possible.
How to achieve true titanium-carbon integration
In particular, a friend who knows a little mechanical knowledge may know that the combination of two materials is actually a very deep knowledge, because under stress, a complex deformation relationship between two different materials will occur, which will affect the entire structure. Both the strength and vibration have a great influence. So how to achieve the real titanium-carbon integration is the university's question.
Foreign countries have conducted a lot of experiments in the process of manufacturing titanium-carbon composite fan blades, and even I understand that in the design process, a method that is not a method is used: first cover the entire carbon fiber blade with titanium alloy material, Then decrease it a little bit, to a certain extent, and find that it can't be reduced any more. At this time, it is to cover the area and shape of the titanium alloy material.
In fact, we only need to look at the documentary that introduces the manufacturing process of carbon fiber fan blades. In fact, the black color of the fan blades we finally saw is not the original color of carbon fiber, but the last one painted.
So many people see the final finished blade and think that only the leading edge material of the blade is not the same, but in fact, under the black pigment, there are two other edges wrapped with titanium alloy.