Category	Brand	Characteristics and uses
Antirust aluminum	LF21	Is the most widely used a kind of anti-rust aluminum, its strength is not high, can not be strengthened by heat treatment, in the annealing state has high plasticity, and good corrosion, good weldability, poor machining. For the manufacture of low-load parts such as fuel tanks, tubing, and liquid containers that require high plasticity and good weldability and work in liquid or gaseous media; The wire can be used to make rivets
	LF13	High corrosion resistance, good welding performance. The thermal conductivity and electrical conductivity are much lower than that of pure aluminum. It can be strengthened by cold deformation processing but not by heat treatment. Suitable for welding structural parts
	LF5 LF10	For aluminum magnesium anti-rust aluminum (LF10 magnesium content slightly higher than LF5) strength and LF3 equivalent, heat treatment can not strengthen, annealing state plasticity, semi-cold hardening plasticity medium, welding performance is good, LF5 is used to make welding parts, pipes and containers and other parts working in liquid. The LF10 is mainly used to make rivets
	LF6	It has high strength and corrosion resistance, good plasticity under annealing and extrusion, and good gas tightness and plasticity of welding seams with argon arc welding. Good machinability. Used for welding containers, stressed parts, aircraft skin and skeleton parts
	LF5-1	The aluminum alloy is not heat-treated and has certain strength, corrosion resistance and good machinability. The surface is beautiful after anodization, and can be processed into optical mechanical parts, ship parts and wire clips
	LF2 LF3	The strength is higher than LF21, the plasticity and corrosion resistance is high, the heat treatment can not be strengthened, the weldability is good (the weldability of LF3 is better than that of LF2), the machinability is better in the cold hardening state, and it can be polished. For the manufacture of medium strength welds, cold stamping parts and containers that work in liquids
Duralumin	LY1	It is the main riveting material for riveting aluminum alloy structure, which has low strength after quenching and natural aging, but has high plasticity and good process performance, the weldability is the same as LY11, the machinability is acceptable, the corrosion resistance is not high, and is widely used as a riveting material for the structure of medium strength and working temperature < 100℃
	LY2	For the heat resistant duralumin, has a high strength, high plasticity during hot deformation, can be strengthened by heat treatment, used in quenching and artificial aging state, good machinability, corrosion resistance than LD7, LD8 heat-resistant forged aluminum is better, in the extrusion of semi-finished products, there is a tendency to form a coarse crystal ring, for the manufacture of load-bearing structural parts working at higher temperatures
	LT4 LY8 LY9	All are rivets with alloy, LY4 has good heat resistance, can be used within 125-250 ° C, LY9 has a high strength, but its common disadvantage is that the rivets must be used within 2-6 hours after quenching. LT8 is suitable for making medium strength rivets
	LY10	Alloy for rivets, with high shear strength, the riveting process is not limited by heat treatment time, but the corrosion resistance is not good. The operating temperature should not exceed 100℃
	LY11	Is the earliest application of a standard duralumin, medium strength, heat treatment can be strengthened, in the quenching and natural aging state of use, spot welding performance is good, gas welding and argon arc welding crack tendency, hot plasticity is acceptable, cutting ability in the quenching aging state is good, corrosion resistance is not high. For making parts and components of medium strength, stamping connecting parts, parts that are partially upset (e.g., screws, rivets)
	LY12	High strength duralumin, can be strengthened by heat treatment, in the annealing and hardening state of medium plasticity, spot welding performance is good, gas welding and argon arc crack tendency, corrosion resistance is not high, machinability in quenching and cold hardening is good, low after annealing. For the manufacture of parts requiring high loads and parts operating below 150 ° C
	LY16 LY17	Heat resistant duralumin, the strength is not high at room temperature and at high temperature high creep strength, high plasticity in hot state, heat treatment can be strengthened, good weldability, corrosion resistance is not high, machinability is good. For the manufacture of parts working at 250-350 ° C, the plate can be used to make welding parts working at room temperature or high temperature
Superduralumin	LC3	Superhard aluminum riveting alloy, heat treatment can be strengthened, high shear strength, corrosion resistance and machining performance is acceptable, riveting is not limited by heat treatment time. Rivets for making mechanical structures
	LC4 LC9	High strength aluminum alloy, in the annealing and hardening state of plasticity medium, can be strengthened by heat treatment, usually in the quenching, artificial aging state used, this time the strength is much higher than the general duralumin, but the plasticity is low, there is a tendency to stress concentration, spot welding performance is good, poor gas welding, after heat treatment of good machining, annealing state is slightly worse, The static fatigue, notch sensitivity and stress corrosion resistance of LC9 are slightly better than LC4. Used to manufacture load-bearing components and high-load parts
Special aluminum	LT1	This is a low alloyed binary aluminum-silicon alloy containing Si5%, its mechanical properties are not high, but the corrosion resistance is very high, and the pressure processing performance is good. Suitable for manufacturing welding rods and welding rods for welding aluminum alloy products
Wrought aluminium	LD2	Medium strength, high plasticity in hot and annealed state, easy to forge, stamping, in quenching and natural state with LF21 as good corrosion resistance, easy spot welding and hydrogen atom welding, gas welding is acceptable. Machinability is acceptable after quenching aging. For the manufacture of plastic and high corrosion resistance, medium load parts and complex forgings
	LD2-1 LD2-2	Good corrosion resistance, good welding performance. For the manufacture of large welded components, forgings and extrusions
	LD5	High strength forged aluminum, hot state has high plasticity, easy forging, stamping, heat treatment can be strengthened, good process performance, corrosion resistance is also good, but there is a tendency to intergranular corrosion, machining and spot welding, seam welding, contact welding performance is good, electric welding, gas welding performance is not good. It is used to manufacture forgings and stamping parts of complex shape and medium strength
	LD6	It has good process performance in hot pressure processing, can be spot welding and seam welding, and is easy to produce stress corrosion tendency and intergranular corrosion sensitivity after heat treatment. Complex shapes and medium-strength forged parts and die forgings can be manufactured
	LD7 LD8 LD9	Heat-resistant forged aluminum, can be strengthened by heat treatment, spot welding, seam welding and contact welding performance is good, electric welding performance is poor, corrosion resistance and machining performance is good, LD8 thermal strength and plasticity than LD7 poor. Used for complex forgings working at high temperatures
	LD10	High strength aluminum has good thermal strength, but poor plasticity in hot state, and other properties are the same as LD5. For the manufacture of high load and simple shape forgings, die forgings
	LD30	For the manufacture of parts of moderate strength (σb > 27kgf/mm2) operating in the range of +50 to -70 ° C and requiring qualified corrosion resistance in wet and seawater media
	LD31	It is used to manufacture parts with low strength (σb > 20kgf/mm2) good corrosion resistance, beautiful decorative surface, working at +50~-70℃, and its alloy has high electrical conductivity after special mechanical treatment, which is widely used in the electrical industry

The difference between a sewn pipe and a seamless pipe
	Indirect extrusion	Direct extrusion
Aluminum ingot processing method	Surface turning, no skin involvement	Skin is not turned, the product may have oxidation layer involved
The action of aluminum ingot and ingot bucket	Integrated flow, frictionless; Metal flow uniformly;	There is relative friction; Uneven metal flow; The product contains coarse crystals.
Product appearance	Both inside and outside walls are smooth; No burning or cracks on the surface;	The exterior finish is average
Mechanical properties of product	The metal flow at the end of the product is uniform; High dimensional accuracy; Good fatigue resistance; Consistent mechanical properties; No layered structure.	The metal flow from end to end of the product is not uniform; Inconsistent mechanical properties; Layered tissue is easy to appear.
Product category	Especially suitable for extruding a variety of ultra-hard alloy rods, pipe profiles (such as 2014, 5056, 7075 series);	The added value of alloy products suitable for extruding general hardness is general
Economy	The price is relatively high, suitable for manufacturing high-precision products	The price is relatively cheap, suitable for the general product system