Edit the classification and universality of alloys in this section.
English: Alloy
Classification of alloys
According to the different structures, the main types of alloys are: (1) mixed alloy (* * * molten mixture), which is an alloy formed by crystallization of various components of the alloy when the liquid alloy solidifies, such as solder and bismuth cadmium alloy. (2) solid molten alloy, in which solid solution is formed when liquid alloy solidifies, such as gold and silver alloy; (3) Intermetallic alloys, that is, alloys in which components form compounds with each other, such as brass (β-brass, γ-brass and ε-brass) composed of copper and zinc. Many properties of alloys are superior to pure metals, so alloys are often used as application materials (see ferroalloy and stainless steel).
Commonality of alloys
All kinds of alloys have the following commonalities: (1) The melting point of most alloys is lower than that of any constituent metal; (2) Hardness is generally greater than that of any metal in its composition; (Special case: Na-K alloy is liquid and used as a heat conductor in atomic reactors) (3) The electrical conductivity and thermal conductivity of the alloy are lower than those of any component metal. Using this characteristic of alloy, materials with high resistance and high thermal resistance can be manufactured. It can also make materials with special properties, such as adding 15% chromium and 9% nickel to iron to obtain a corrosion-resistant stainless steel, which is suitable for chemical industry. (4) Some alloys have strong corrosion resistance (such as stainless steel). 2. Common alloys are ductile iron, manganese steel, stainless steel, brass, bronze, white copper, solder, hard aluminum, 18K gold and 18K platinum.
Edit this part of steel
Brief introduction of steel
Steel is an alloy of iron with carbon, silicon, manganese, phosphorus, sulfur and a small amount of other elements. Except Fe, the content of C plays a major role in the mechanical properties of steel, so it is collectively called iron-carbon alloy. It is the most important and commonly used metal material in engineering technology.
Classification and nature
According to the different carbon content, iron-carbon alloys can be divided into steel and pig iron. Steel is an iron-carbon alloy with a carbon content of 0.03% ~ 2%. Carbon steel is the most commonly used common steel, which is easy to smelt, easy to process and low in price, and can meet the use requirements in most cases, so it is widely used. According to the different carbon content, carbon steel is divided into low carbon steel, medium carbon steel and high carbon steel. With the increase of carbon content, the hardness of carbon steel increases and the toughness decreases. Alloy steel is also called special steel. Adding one or more alloying elements on the basis of carbon steel changes the structure and properties of steel, thus having some special properties, such as high hardness, high wear resistance, high toughness and corrosion resistance. The alloying elements often added in steel are silicon, tungsten, manganese, chromium, nickel, molybdenum, vanadium, titanium and so on. China is rich in alloy steel resources. Except for the lack of chromium and the low grade of cobalt and manganese, the reserves of tungsten, molybdenum, vanadium, titanium and rare earth metals are all very high. At the beginning of 2 1 century, the proportion of alloy steel in the total steel output will increase greatly.
About pig iron
Iron-carbon alloy with carbon content of 2% ~ 4.3% is called pig iron. Pig iron is hard and brittle, but it is resistant to compression and wear. According to the different forms of carbon in pig iron, it can be divided into white iron, gray iron and ductile iron. The carbon in white iron is distributed in the form of Fe3C, and the fracture is silvery white. It is hard and brittle, so it can't be machined. It is the raw material for steelmaking, so it is also called steelmaking pig iron. The fracture of gray cast iron with carbon distributed in flake graphite is silver gray, which is easy to cut, cast and wear-resistant. If carbon is distributed in spherical graphite, it is called ductile iron, and its mechanical properties and machinability are close to those of steel. Special cast iron can be obtained by adding special alloying elements to cast iron. If chromium is added, the wear resistance can be greatly improved, which has a very important application under special conditions. In view of this elite talent, which is also the most scarce talent in China at present, there is Steel Talent Network, which is a professional recruitment and job search website for ferroalloy industry.
Edit this section of aluminum alloy.
brief introduction
Aluminum alloy plastic material
Aluminum is a widely distributed element, and its content in the earth's crust is second only to oxygen and silicon, and it is the highest among metals. Pure aluminum has a low density of 2.7 g/cm3, good thermal and electrical conductivity (second only to Au, Ag and Cu), good ductility and high plasticity, and can be used in various mechanical processing. Aluminum has active chemical properties, and rapidly oxidizes in air to form a dense and firm oxide film, so it has good corrosion resistance. However, the strength of pure aluminum is low, and only by alloying can various aluminum alloys used as structural materials be obtained.
Features and attributes
The outstanding characteristics of aluminum alloy are low density and high strength. Aluminum-manganese and aluminum-magnesium alloys formed by adding manganese and magnesium to aluminum have good corrosion resistance, good plasticity and high strength. They are called rust-proof aluminum alloys and are used to manufacture oil tanks, containers, pipes and rivets. The strength of hard aluminum alloy is higher than that of rust-proof aluminum alloy, but its corrosion resistance decreases. These alloys include aluminum-copper-magnesium system and aluminum-copper-magnesium-zinc system. The strength of the newly developed high-strength hard aluminum is further improved, but the density is lower than that of ordinary hard aluminum 15%, which can be extruded and can be used as motorcycle frames and rims. Al-Li alloy can be used to manufacture aircraft parts and high-grade sports equipment that bear heavy loads.
App application
At present, high-strength aluminum alloy is widely used in the manufacture of aircraft, ships and trucks, which can increase its load capacity and speed, and has the characteristics of seawater corrosion resistance and magnetic avoidance.
Edit this aluminum alloy overview.
Aluminum alloy aluminum alloy is the most widely used non-ferrous metal structural material in industry, which has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding, chemical industry and other industries. With the rapid development of science and technology and industrial economy in recent years, the demand for aluminum alloy welded structural parts is increasing, which makes the research on aluminum alloy weldability deepen. The wide application of aluminum alloy promotes the development of aluminum alloy welding technology, and the development of welding technology expands the application field of aluminum alloy, so aluminum alloy welding technology is becoming one of the research hotspots. Pure aluminum has a low density (ρ=2.7g/m3), about 65,438+0/3 of that of iron, and a low melting point (660℃). Aluminum has a face-centered cubic structure, so it has high plasticity (δ: 32-40%, ψ: 70-90%), is easy to process, and can be made into various profiles. Good corrosion resistance; However, the strength of pure aluminum is very low, and the σb value in the annealed state is about 8kgf/mm2, so it is not suitable for structural materials. Through long-term production practice and scientific experiments, people gradually strengthened aluminum by adding alloying elements and adopting heat treatment, and obtained a series of aluminum alloys. The alloy formed by adding some elements can not only keep the advantages of pure aluminum, such as light weight, but also have high strength, and σb values can reach 24 ~ 60 kgf/mm2 respectively. This makes its "specific strength" (the ratio of strength to specific gravity σb/ρ) better than many alloy steels, making it an ideal structural material, which is widely used in machinery manufacturing, transportation machinery, power machinery and aviation industry. Aircraft fuselage, skin and compressor often use aluminum alloy to reduce their own weight. Replacing steel plate with aluminum alloy can reduce the structural weight by more than 50%. Aluminum alloy has low density, but its strength is relatively high, close to or higher than that of high-quality steel. Good plasticity, can be processed into various profiles, and has excellent electrical conductivity, thermal conductivity and corrosion resistance. It is widely used in industry, and its usage is second only to steel. Aluminum alloys are divided into two categories: cast aluminum alloys, which are used as cast; Deformed aluminum alloy can withstand pressure processing and can be processed into various forms and specifications of aluminum alloy materials. Mainly used for manufacturing aviation equipment, building doors and windows, etc. Aluminum alloys can be divided into wrought aluminum alloys and cast aluminum alloys according to processing methods. Wrought aluminum alloys can be divided into non-heat treated aluminum alloys and heat treated aluminum alloys. Non-heat treatment strengthening type can not improve mechanical properties through heat treatment, but only through cold working deformation, mainly including high-purity aluminum, industrial high-purity aluminum, industrial pure aluminum and rust-proof aluminum. Heat-treatable strengthened aluminum alloys can improve their mechanical properties by means of heat treatment such as quenching and aging, which can be divided into hard aluminum, forged aluminum, superhard aluminum and special aluminum alloys. Some aluminum alloys can obtain good mechanical properties, physical properties and corrosion resistance through heat treatment. According to chemical composition, cast aluminum alloys can be divided into Al-Si alloy, Al-Cu alloy, Al-Mg alloy, Al-Zn alloy and Al-RE alloy. Among them, Al-Si alloy includes simple Al-Si alloy (which can not be strengthened by heat treatment, with low mechanical properties and good castability) and special Al-Si alloy (which can be strengthened by heat treatment, with high mechanical properties and good castability). The torch of the 2008 Beijing Olympic Games Xiangyun Torch is made of aluminum.
Edit this Duan Chun aluminum product.
Pure aluminum can be divided into two categories: smelting products and pressure processing products. The former is represented by the chemical composition al, and the latter is represented by the Chinese pinyin LU (aluminum, industrial). Aircraft All kinds of aircraft use aluminum alloy as the main structural material. Aircraft skins, beams, ribs, stringers, frames and landing gears can all be made of aluminum alloy. The amount of aluminum varies according to the purpose of the aircraft. Economic-oriented civil aircraft are widely used because of the low price of aluminum alloy. For example, the aluminum alloy used in Boeing 767 aircraft accounts for about 865,438+0% of the structural weight of the aircraft. Because military aircraft require good performance, the amount of aluminum is relatively reduced. For example, the F- 15 high-performance fighter with a maximum flight speed of Mach 2.5 uses only 35.5% aluminum alloy. Some aluminum alloys have good low temperature performance, and are neither cold nor brittle at-183 ~-253 [2OC]. They can work in the environment of liquid hydrogen and liquid oxygen, but they are not compatible with concentrated nitric acid and unsymmetrical dimethylhydrazine. The fuel tank, oxidizer tank, inter-tank section, inter-stage section, tail section and instrument cabin of Apollo spacecraft launched by Saturn V carrier rocket are all made of aluminum alloy. The crew cabin, front fuselage, middle fuselage, rear fuselage, vertical tail, flap, lifting aileron and horizontal tail of the space shuttle are all made of aluminum alloy. The main structural material of various artificial earth satellites and space probes is also aluminum.
Edit the repair process of forgings in this section.
Damage repair is an important part of aluminum alloy die forging process. Because aluminum alloy is soft at high temperature, with high viscosity and poor fluidity, it is easy to stick to the mold, resulting in various surface defects (folding, burrs, cracks, etc. ). Before the next process, it must be polished and repaired to remove surface defects, otherwise the defects will be further expanded in the subsequent process, and even the forgings will be scrapped. The tools used to repair the damage include pneumatic grinder, pneumatic small milling cutter, electric small milling cutter and flat shovel. Before repairing, the defective parts should be found by corrosion, and the repaired parts should be smooth transition, and the width should be 5 ~ 10 times of the depth.
Edit this section of pressure processing aluminum alloy.
Aluminum alloy pressure processing products are divided into seven categories: rust prevention (LF), hardness (LY), forging (LD), superhard (LC), cladding (LB), special (LT) and brazing (LQ). The commonly used aluminum alloy materials are annealed (M-annealed), quenched (Y) and hot rolled (R).
Edit this part of aluminum material.
Aluminum and aluminum alloys processed into certain shapes are collectively called aluminum materials, including plates, belts, foils, tubes, rods, wires and profiles. Aluminum alloy sheet
1. aluminum-plastic plate
Aluminum-plastic plate is a new type of material, which is composed of 3003 Al-Mn alloy and 5005 Al-Mg alloy after surface treatment and paint coating, with pe plastic as the core layer and polymer adhesive film compounded by a series of processes. It not only retains the main characteristics of raw materials (aluminum alloy plate, non-metallic polyethylene plastic), but also overcomes the shortcomings of raw materials, and then obtains many excellent material properties. Product features: colorful decoration, weather resistance, corrosion resistance, impact resistance, fire prevention, moisture resistance, sound insulation, heat insulation, earthquake resistance, light weight, easy processing and molding, easy handling and installation. Specification of aluminum-plastic plate: thickness: 3mm, 4mm, 6mm, 8mm, width:1220mm, length:1500mm, 2440mm, 3000mm, 6000mm. Standard size of aluminum-plastic plate: 1220mm * 2400.
2. Aluminum veneer
All aluminum veneers are made of high-quality aluminum alloys from world-renowned large enterprises, and then sprayed with American PPG or Aksu PVDF fluorocarbon coatings. Aluminum veneer is mainly composed of panel, reinforcement of bones and muscles, ear hook and so on. Features of aluminum veneer: light weight, good rigidity, high strength, nonflammability, good fire resistance, good processing technology, wide color selection, excellent decorative effect, easy recycling and environmental protection. Application of aluminum veneer: building curtain wall, column beam, balcony, partition bag, interior decoration, advertising signboard, vehicle, furniture, booth, instrument shell, subway marine tools, etc.
3. Aluminum honeycomb panel
Aluminum honeycomb panel adopts composite honeycomb structure, which is made of high-quality 3003H24 alloy aluminum plate or 5052AH 14 high-manganese alloy aluminum plate and aluminum alloy honeycomb core material by hot pressing. Aluminum honeycomb panel provides architects with rich choices from panel materials, shapes, joints, installation systems to colors and surface treatment, which can show rich roof performance and have excellent design freedom. It is a new material with convenient construction, ideal comprehensive performance and remarkable thermal insulation effect, and its excellent performance has attracted people's attention. There is no standard size of aluminum honeycomb panels, which are all customized by the factory according to the design drawings, and are widely used in the fields of building exterior wall decoration (especially suitable for high-rise buildings), interior wall ceiling, partition walls, doors, insulated carriages, billboards and so on. This product will inject green, environmental protection and energy-saving fresh strength into China building materials market.
4. Aluminum honeycomb perforated sound-absorbing ceiling board
Aluminum honeycomb perforated sound-absorbing ceiling board is composed of perforated aluminum alloy panel and perforated back plate. It is directly bonded with the aluminum honeycomb core by high-quality glue to form an aluminum honeycomb sandwich structure, and a layer of sound-absorbing cloth is stuck between the honeycomb core, the panel and the back panel. Because the honeycomb core in the honeycomb aluminum plate is divided into many closed cells, the air flow is prevented, the sound wave is hindered, the sound absorption coefficient is improved (above 0.9), and the strength of the plate itself is improved, so that the size of the veneer can be made larger, and the design freedom is further increased. According to room acoustics design, different perforation rates can be designed, and the sound absorption coefficient of composite structure can be controlled within a certain range, which can not only achieve the design effect, but also control the cost reasonably. By controlling the perforation aperture and spacing, and changing the perforation rate according to customer requirements, the maximum perforation rate
Edit casting aluminum alloy in this section.
Cast aluminum alloy (ZL) can be divided into four categories, namely, silicon, copper, magnesium and zinc, with code names 100, 200, 300 and 400 respectively. In order to obtain high-quality precision castings of various shapes and specifications, aluminum alloys for casting generally have the following characteristics. (1) Good fluidity is used to fill the narrow part of the tank (2). The melting point is lower than that of ordinary metal, but it can meet the requirements of most cases (3) Good thermal conductivity, the heat of molten aluminum can be quickly transferred to the mold, and the casting cycle is short (4) Harmful gases such as hydrogen in the melt can be effectively controlled by treatment (5) When aluminum alloy is cast, there is no tendency of hot embrittlement and tearing (6). Strong corrosion resistance (7) It is not easy to produce surface defects, and the surface of the casting has good surface smoothness and luster, and it is easy to carry out surface treatment (8) The cast aluminum alloy has good processability, and can be cast by mold, hard mold, wet sand mold and dry sand mold, investment gypsum mold, vacuum casting, low-pressure and high-pressure casting, extrusion casting, semi-solid casting, centrifugal casting, etc. To produce products with different uses, varieties and specifications. Cast aluminum alloy is widely used in automobiles, such as engine cylinder head, intake manifold, piston, wheel hub, steering booster housing and so on.
Edit this section of high strength aluminum alloy.
High-strength aluminum alloy refers to aluminum alloy with tensile strength greater than 480 MPa, which mainly includes antirust aluminum alloy, hard aluminum alloy, superhard aluminum alloy, forged aluminum alloy and aluminum-lithium alloy.
Edit aluminum alloy defect repair in this section.
In the process of aluminum alloy production, casting defects such as shrinkage cavity, sand hole, air hole and slag inclusion are easy to occur. How to repair defects such as air holes in aluminum alloy castings? If electric welding, argon arc welding and other equipment are used for repair, it is easy to produce side effects such as thermal deformation due to large heat release, which can not meet the requirements of repair welding. The cold welding repair machine uses the principle of high frequency electric spark instantaneous discharge and non-thermal surfacing to repair casting defects. Because the heat affected zone of cold welding is small, it will not cause annealing deformation, cracks, hard spots and hardening of the base metal. Moreover, the welding strength is high, the auxiliary materials and the matrix are solidified after melting at the same time, and the combination is firm, which can be processed by grinding, milling, filing and the like. , and dense does not fall off. Cold welding repair machine is an ideal method to repair tiny defects such as air holes and sand holes in aluminum alloy.
In this section, edit the typical uses of aluminum alloys.
1050 extrusion coils, various hoses and fireworks powder used in food, chemical and brewing industries require high corrosion resistance and formability, but the strength is not high. Chemical equipment is its typical use. 1 100 is used to process parts that require good formability and high corrosion resistance but do not require high strength. For example: chemical products, food industry devices and storage containers, plate processing parts, deep-drawn or spinning concave containers, welding parts, heat exchangers, printed boards, nameplates, reflective devices 1 145 packaging and insulating aluminum foil, heat exchangers 1 199 electrolytic capacitor foil, optical reflective deposition film/. Transformer belt 20 1 1 screws and machined aircraft heavy-duty, forgings, thick plates and extrusions, wheels and structural parts, first-class fuel tank and spacecraft parts of multistage rockets, truck frame and suspension system parts 20 17 are the first batch of 2XXX series alloys applied in industry. At present, the application scope is relatively narrow, mainly rivets, general mechanical parts, structures and transportation structural parts. Propeller and accessories 2024 Aircraft structures, rivets, missile parts, truck hubs, propeller parts and other structural parts 2036 Automobile body sheet metal parts 2048 Aerospace structural parts and weapon structural parts 2 124 Aerospace structural parts 22 18 Piston, cylinder head, impeller and compressor ring of aero-engine and diesel engine 22 19 Aerospace rocket. 23 19 welded and drawn covered electrode alloy 22 19 and filled solder 26 18 die forgings and free forgings. Piston and aero-engine parts 2A0 1 structural rivet 2A02 with working temperature less than or equal to 100℃, axial compressor blade 2A06 of turbojet engine with working temperature of 150~250℃, and aircraft structural rivet 2a 125 ~ 250℃. Alloy A0 1 H is used to manufacture aircraft structural rivets 2A 1 1 aircraft medium strength structural parts, propeller blades, vehicles and building structural parts with working temperature less than or equal to 100℃. 2A 12 Medium strength bolts and rivets for aircraft skin, frame, ribs, spars, rivets, etc. , structural parts 2A 14 for construction and transportation, free forgings and die forgings 2A 16, aerospace parts working at 250~300℃, welded containers and airtight cabins 2A 17, aircraft parts 2A50 and 2A60 with complicated shapes and moderate strength, compressor impeller, guide wheel and A60 for aircraft engines. Aircraft engine piston, guide vane, disk and other parts with high working temperature, such as compressor blade, impeller, piston and expansion ring, are used to process parts and components that require good formability, high corrosion resistance and good weldability, or both these properties and higher strength than 1XXX alloy. Such as kitchen utensils, processing and storage devices for food and chemical products, tanks and tanks for transporting liquid products, all-aluminum tanks for various pressure vessels and pipelines processed with thin plates, and other parts with higher strength than 3003 alloy, production and storage devices for chemical products, thin plate processing parts, building processing parts, building tools, and various lamp parts, such as 3 105 room partitions, baffles, movable roof panels, etc. Building materials are similar to 5005 and 3003 alloys of industrial equipment such as food, with medium strength and good corrosion resistance. Used as conductor, cooker, dashboard, shell and architectural decoration. The anodic oxide film is brighter than the oxide film on 3003 alloy, which is in harmony with the color of 6063 alloy. 5050 sheet can be used as the inner lining of refrigerators and freezers, automobile air pipes, oil pipes and agricultural irrigation pipes. It can also process 5052 thick plates, pipes, bars, special-shaped materials and wires. This alloy has good formability, corrosion resistance, candle resistance, fatigue strength and moderate static strength, and is used to manufacture 5056 magnesium alloy and cable sheath rivets, zippers, nails, etc. Used for aircraft fuel tanks and oil pipes, as well as sheet metal parts, instruments, street lamp brackets and rivets, hardware products, etc. of traffic vehicles and ships. Aluminum-clad wire is widely used to process the outer cover of agricultural insect traps and other occasions where high corrosion resistance is needed. 5083 is used in occasions that need high corrosion resistance, good weldability and medium strength, such as welding parts of ships, automobiles and aircraft plates; Pressure vessel, refrigeration device, TV tower, drilling equipment, transportation equipment, missile parts, armor, etc. 5086, which needs strict fire protection, is used in places that need high corrosion resistance, good weldability and medium strength. For example, 5 154 ships, automobiles, airplanes, cryogenic equipment, TV towers, drilling rigs, transport equipment, missile parts and welded structures such as decks, storage tanks, pressure vessels, ship structures and offshore facilities, transport tanks 5 182 thin plates are used for processing cans, and 5252 automobile body plates, steering wheels, reinforcements, brackets and other parts are used. After anodizing, there are bright and transparent oxide film 5254, chemical product containers such as hydrogen peroxide 5356, aluminum-magnesium alloy covered electrode with magnesium content greater than 3% and welding wire 5454 welding structure, pressure vessels, marine facilities, pipelines, 5456 steel plates, high-strength welding structures, storage tanks, pressure vessels, ship materials, 5457 automobiles and other equipment polished anodizing decorations, chemical product storage containers such as 5A02 hydrogen peroxide, etc. Welding wires, rivets, strength welded structural parts in ship structural parts 5A03, cold stamping parts, welded containers and welding wires can be used to replace 5A02 alloy 5A05 welded structural parts, aircraft skin skeleton 5A06 welded structural parts, cold die forgings, welded and drawn container stress parts, aircraft skin bone parts 5A 12 welded structural parts, bulletproof deck 6005 extruded profiles and pipes. Used for structural parts with strength and height greater than 6063 alloy, such as ladders and TV antennas. 6009 Automobile Body Plate 60 10 Sheet: Automobile Body 606 1 requires various industrial structures to have certain strength, weldability and corrosion resistance, such as pipes, rods and strips used for manufacturing trucks, tower buildings, ships, trams, furniture, mechanical parts and precision machining. Irrigation pipes and extrusion materials for vehicles, benches, furniture, fences, etc. 6066 Forging and Welding Structure Extrusion Material 6070 Extrusion Material and Pipe for Heavy-duty Welding Structure and Automobile Industry 6 10 1 High-strength Bar, Electrical Conductor and Cooling Equipment for Automobile 15 1 Used for die forging crankshaft parts, machine parts and production rolling rings. Used for 620 1 high strength conductive rod wire 6205 thick plate, pedal and high impact extrusion 6262. The corrosion resistance of threaded high stress parts is better than that of 20 1 1 and 20 17 alloys. After anodic oxidation treatment, 6463 pipes for water and oil, profiles of buildings and various appliances, and 6A02 aircraft engine parts for automobile decoration have bright surfaces, and 7005 forgings and die forgings with complex shapes are extrusion materials, which are used to manufacture welded structures with high strength and fracture toughness, such as trusses, bars and containers of transport vehicles. Large heat exchangers, and parts that cannot be solid-solution treated after welding; It can also be used to manufacture sports equipment, such as tennis rackets and softball bats, 7039 frozen containers, cryogenic equipment and storage boxes, fire-fighting pressure equipment, military equipment, armor plates and missile devices. 7049 can be used to forge parts with the same static strength and high stress corrosion cracking resistance as 7079-T6 alloy, such as aircraft and missile parts-landing gear hydraulic cylinder and extrusion parts. The fatigue performance of the parts is almost the same as that of 7075-T6 alloy, while the 7050 aircraft structural parts with higher toughness are made of plate, extrusion, free forgings and die forgings. The alloy requirements for manufacturing this kind of parts are: high spalling corrosion resistance, stress corrosion cracking ability, fracture toughness and fatigue resistance, 7072 air conditioning aluminum foil and ultra-thin strip; Cladding layers of 22 19, 3003, 3004, 5050, 5052, 5 154, 606 1, 7075, 7475, 7 178 alloy plates and pipes are used to manufacture aircraft structures and futures. He requires high strength and corrosion resistance. T736 material has good comprehensive properties, namely, high strength, spalling corrosion resistance, stress corrosion cracking resistance, fracture toughness and fatigue strength. 7 178 is used to manufacture aluminum clad plates, wing frames and stringers. This requires aerospace vehicles to have high compressive yield strength. Other parts with high strength and fracture toughness 7A04 aircraft skin, screws, and stress components such as girders, frames, ribs, landing gear, etc.