其實航空產業在 1970 年代就已經採用複合材料。從 1985 年起開始被用於製造機尾，例如空中巴士的 A310 廣體客機。但直到過去十年複合材料才有突破性的發展，並大量應用於波音 787 客機與空中巴士 A350。兩款飛機的機身幾乎有一半是由碳纖維塑膠及其它複合材料所製成，以材質更輕的碳纖維取代多數金屬零件，從而省下燃料費。金屬會有腐蝕與疲勞等問題，一定時間到了就要更換，複合材料不會有這樣的問題，可以延長飛機的壽命。大量採用複合材料的飛機，組裝時必須格外小心。例如，以往金屬材料使用多，如果組裝過程稍微碰撞還可以修補，複合材料卻要求完全不能碰撞。2024 年 1 月 2 日，日本航空 A350 客機與日本海上保安廳航機發生嚴重擦撞事故，是首度 A350 客機全毀事故，機上 379 人全數逃出，這場事故成為複合材料安全性的關鍵測試。這起事故乘客和機組員得以在機體還完好的情況下全數平安撤離，讓人們對複合材料安全性增加了信心。鋁的熔點為攝氏 600 度左右且能導熱，碳纖維卻能承受約 6 倍的高溫，在當天的情況下，碳纖維提供了隔熱層保護。至於複合材料的燃燒，究竟是否釋放出有毒物質，以至於對人體產生危害，目前仍無法判斷。這些傷害可能需要一段時間後才能顯現出來。引擎製造商也想方設法降低引擎重量，大型噴射機平均重達 6,350 公斤。根據勞斯萊斯，若在風扇葉片與機殼等部分使用複合材料，廣體客機的引擎重量可望降低 340 公斤。
飛機製造商使用大量複合材料，已經是愈來愈明顯的趨勢。波音和空中巴士近年來將熱塑性複合材料 (thermoplastics) 視為改變飛機製造方式的關鍵技術，目標是取代傳統的鋁合金和熱固性複合材料 (thermoset)，提升飛機結構設計與生產效率。與熱固性材料不同，熱塑性複合材料可重複加熱塑形，並能透過超音波焊接取代傳統鉚釘與鈦合金接點，大幅縮短加工時間、適合量產。這不僅能減輕機體重量，還能簡化製程並提升產能。
憑藉其輕量、高強度、耐衝擊與可回收性，熱塑性複合材料正逐步取代傳統金屬與熱固性材料，成為波音與空中巴士下一代客機的研發重點。
-The Trend of Composite Materials in AircraftThis article summarizes the materials commonly used in aircraft manufacturing.1. Aluminum AlloysTo reduce the weight of aircraft, aluminum alloys are often used for the body material. This type of aluminum alloy used in aircraft is generally referred to as duralumin, which is made by mixing aluminum, copper, magnesium, and manganese. It is characterized by its lightness, strength, and durability, making it a very suitable alloy for aircraft materials.The engine interior, which produces high temperatures and pressures, uses magnesium alloys, titanium alloys, and nickel alloys. Another newer material, titanium aluminide, is also starting to be used to reduce engine weight.2. Titanium AlloysTitanium is an important material in modern aircraft manufacturing. It has the properties of high ductility, corrosion resistance, heat resistance, and high strength. It offers strength similar to steel, but is much lighter in weight. Titanium alloys can be applied to many places, such as aircraft frames, engine blades, and landing gear. Titanium can also be combined with composite materials to create lighter-weight materials.The use of titanium in aircraft manufacturing has been increasing. In the first version of the Boeing 747 developed in the 1960s, titanium content was less than 3%, but in the first version of the Boeing 777 in the mid-1990s, titanium use ratio reached nearly 9%. In modern passenger jets such as the Boeing 787-9, the titanium content is closer to 15%.More than half of the world's titanium is used in the aerospace industry. After the outbreak of the Russia-Ukraine war, the titanium supply chain faced serious problems, as most of the world's titanium comes from Russia. VSMPO-AVISMA, a Russian company, is the world's largest titanium producer. It is estimated that one-third of the titanium used by Boeing comes from Russia; Airbus has a higher ratio, with about half of its titanium needs coming from Russia.Although Russia is not the main source of titanium ore (these ores come from countries such as China, Australia, and Kazakhstan), its importance in the titanium supply chain is in the subsequent processing stage. VSMPO-AVISMA is the main producer of titanium sponge. Titanium sponge is the raw material for titanium processing, which will then be turned into various aircraft components.In February 2022, after Russia invaded Ukraine, Boeing and Airbus both announced that they would reorganize their titanium supply chains, stopping buying titanium from Russia and turning to major players in the titanium market, such as OSAKA Titanium Technologies Co., Ltd. (OSAKA Titanium) and Toho Titanium Co., Ltd. (Toho Titanium).3. Composite MaterialsAs aerospace technology continues to advance, new manufacturing materials have also emerged, with composite materials being one of the most popular. Composite materials are made up of fiber materials and plastics, and are used to replace traditional alloy materials. Composite materials have excellent elasticity and durability, and are lighter in weight, so they are often used in aircraft landing gear, as well as in aircraft wings, such as flaps, horizontal, and vertical tail wings.The aerospace industry actually began using composite materials in the 1970s. From 1985, it began to be used to manufacture the tail, such as the Airbus A310 wide-body aircraft. However, it was not until the past decade that composite materials saw a breakthrough in development, and were widely used in the Boeing 787 and Airbus A350. The fuselages of both aircraft are almost half made of carbon fiber plastics and other composite materials. The use of lighter carbon fiber instead of most metal parts saves fuel. Metals can corrode and fatigue, and must be replaced after a certain period of time. Composite materials do not have these problems and can extend the life of the aircraft.Aircraft that use a lot of composite materials must be assembled with extra care. For example, in the past, when metal materials were used more, if there was a slight collision during assembly, it could be repaired. However, composite materials require that there be no collisions at all.On January 2, 2024, a Japan Airlines A350 passenger plane and a Japan Coast Guard aircraft collided in a serious accident. This was the first A350 passenger plane to be completely destroyed. All 379 people on board escaped. This accident became a critical test of the safety of composite materials.The fact that passengers and crew were able to evacuate safely with the fuselage still intact gave people more confidence in the safety of composite materials. Aluminum melts at around 600 degrees Celsius and conducts heat, but carbon fiber can withstand about six times the heat. In this case, carbon fiber provided thermal insulation.As for whether the burning of composite materials releases toxic substances that can harm the human body, it is still impossible to judge at present. These injuries may take some time to manifest.Engine manufacturers are also trying to find ways to reduce engine weight. Large jet engines weigh an average of 6,350 kilograms. According to Rolls-Royce, if composite materials are used in parts such as fan blades and housings, the weight of wide-body aircraft engines could be reduced by 340 kilograms.The use of large amounts of composite materials by aircraft manufacturers is becoming an increasingly clear trend.