Aluminum alloy type, Heat treatment, Anodizing- JCG Industrial Co., Ltd. Manufacturing Factory

Processing type classification: Stretching materials are divided into non-heat-treated alloys and heat-treated alloys
Non-heat treatment alloys: pure aluminum-1000 series, aluminum-manganese alloy-3000 series, aluminum-silicon alloy-4000 series, aluminum-magnesium alloy-5000 series.
Heat treatment alloys: aluminum-copper-magnesium alloy-2000 series, aluminum-magnesium-silicon alloy-6000 series, aluminum-zinc-magnesium alloy-7000 series.

Aluminum alloy code:
1070-H14 (pure aluminum)
5052-H32 (non-heat-treated alloy)
6061-T6 (heat-treated alloy)
The first digit: indicates the main addition of alloying elements.
1: Pure aluminum
2: The main added alloying element is copper
3: The main added alloying elements are manganese or manganese and magnesium
4: The main added alloying element is silicon
5: The main added alloying element is magnesium
6: The main added alloying elements are silicon and magnesium
7: The main added alloying elements are zinc and magnesium
8: New alloys that do not belong to the alloy series listed above
The second digit: indicates the alloy with the content of the main added alloying elements or the content of the impurity components in the original alloy.
0: Table original alloy
1: The original alloy is revised for the first time
2: The original alloy of the table has been revised for the second time
Third and fourth digits:
Pure aluminum: indicates the original alloy
Alloy: indicates the code name of individual alloy
-The Hn or Tn at the back indicates the degree of work hardening state or heat treatment state
-H: indicates the degree of chain symbol for non-heat-treated alloys
-Tn: represents the chain degree symbol of heat-treated alloy
       
Heat treatment of aluminum and aluminum alloys

Chain degree symbol: If the addition of alloying elements is not enough to fully meet the requirements, cold working, quenching, aging treatment and annealing must be used to obtain the required strength and performance. The process of these treatments is called tempering, and the result of tempering is the degree of chain.
Symbol
F	Chain degree of manufacturing state Finished products manufactured without a specific chain degree, such as extruded, hot-rolled, forged products, etc.
H112	The finished product in the manufacturing state without deliberately controlling the degree of work hardening, but the mechanical properties must be guaranteed.
O	Annealing chain degree Completely recrystallized and in the softest state. If it is a heat-treated alloy, it must be cooled slowly from the annealing temperature to completely prevent the quenching effect.
H	Work-hardened chain degree H1n: those subjected to cold working and work hardening. H2n: Appropriate annealing treatment is applied after work hardening. H3n: Stabilize after work hardening. n represents the degree of work hardening with numbers from 1 to 9. n=2 means 1/4 hard. n=4 means 1/2 hard. n=6 means 3/4 hard. n=8 means hard. n=9 means super hard.
T	Add T1-, natural aging after high temperature processing and cooling. Extrusion is cooled rapidly after hot processing, and then is subjected to regular temperature ten-effect hardening treatment. It can also be subjected to corrective processing that does not affect the strength. This quenching and tempering is suitable for alloys that have a quenching effect after cooling after hot processing, such as 6063. T3-The purpose of cold working after solution treatment is to improve strength, flatness and dimensional accuracy. T36-T3 is 6% cold processed. T361-The cold working degree is greater than T3. T4- Natural aging treatment after solution treatment. T5-After hot processing, it is quenched and then artificially aged. The purpose of artificial aging is to improve the material's mechanical properties and dimensional stability. It is suitable for alloys that have a quenching effect after hot working and cooling, such as 6063. T6-The artificial aging treatment is applied after the solution treatment. This is a representative heat treatment of heat-treated alloys, and superior strength can be obtained without cold working. After the solution treatment, cold working is applied to improve dimensional accuracy or correction. If higher strength is not guaranteed, it can also be regarded as T6 chain degree. T61-After solution treatment, it is treated with warm water quenching water and then artificial aging treatment. The purpose of warm water quenching is to prevent deformation. T7-Stabilization treatment is applied after solution treatment (also the temperature or time of artificial aging treatment is higher or longer than that of T6 treatment). Its purpose is to improve resistance to hard corrosion cracking and prevent deformation during quenching. T7352-Remove residual stress after solution treatment and apply over-aging treatment (also the temperature or time of artificial aging treatment is higher or longer than T6 treatment). The purpose is to improve the resistance to hard corrosion cracking. After solution treatment, a compression process of 1~5% permanent deformation is applied to eliminate residual stress. T8-After solution treatment, cold working is applied and then artificial aging treatment is applied, and the cross-section reduction rate during cold working is 3% and 6% respectively for T83 and T86. T9-The artificial aging treatment after solution treatment, and finally cold working, the purpose of the final cold working is to increase the strength.

Aluminum processing problems and countermeasures

1. Common defects in aluminum alloy forming and processing
Missing	Improve strategy
The blank is defective:
1. Cracks in the wall or flange of the hollow shell	1. Improve quality control
2. Ears	2. Annealing
2. The tool is defective
1. At the beginning of the extension, the bottom of the hollow shell is torn。	1. Increase the fillet of the punch or die.
2. At the end of the extension, the bottom side of the hollow shell is torn.	2. Increase the middle extension, Choose better quality materials; If it is a square hollow shell Increase the die clearance of the corner.
3. Extension scratches.	3. Use special extension butter (materials must be treated with phosphate Or copper plating), and then polish the tool surface (chrome plating), using materials that are not prone to scratches.
4. The edge of the finished product is serrated, and the surface of the shell has wrinkles.	4. Re-roll the mold or replace the extension mold.

 

2. Common defects in sulfuric acid anode treatment:
Missing	Improve strategy
Electric shock burns or perforations at a local position of the work object	When placing the work object in the processing tank, pay attention to the distance from the cathode to avoid contact.
The oxide film is very loose and can be wiped off by hand	Reduce the temperature. Shorten the oxidation time. Reduce current density.
Local surface of oxide film is corroded	Strengthen the washing after oxidation.

 

3. Common defects in chromic acid anode treatment:
Missing	Improve strategy
Work object is burned	Avoid contact. Reduce the voltage.
Parts are corroded into deep pits	Adjust to increase CrO3
Blackening of the film	Strengthen the washing after oxidation.

 

4. Common defects in hard anodizing treatment:
Missing	Improve strategy
The thickness of the oxide film is not enough	Increase the oxidation time. Increase the current density.
The hardness of the oxide film is not enough	Lower the electrolyte temperature. Reduce current density. Reduce the oxidation time.
The oxide film is broken down And burn out work objects	Try to make the contact good. Strengthen electrolyte cooling.

Aluminum anodizing
It is widely used in industry and has 6 popular features.

1. Prevent corrosion
The anodized film is sufficiently stable in the atmosphere, and the oxide film on the aluminum surface is used as a protective layer. The oxide film obtained by anodic oxidation of aluminum in chromic acid solution is dense and has good corrosion resistance; the oxide film obtained from sulfuric acid solution has larger pores than the former, but its film layer is thicker and has strong adsorption capacity. The filling and sealing treatment is also very good in corrosion resistance. The chromic acid anodic oxidation method is particularly suitable for anodic oxidation treatment of riveted parts and welded parts.
2. Decorative painting
The refined aluminum products are chemically or electrochemically polished and then anodized with sulfuric acid solution to obtain an oxide film with higher transparency. This kind of oxide film can absorb many kinds of organic dyes and inorganic dyes, so it has a variety of bright colors. This color film is both an anti-corrosion layer and a decorative layer. Under some special process conditions, a protective and decorative oxide film similar in appearance to porcelain can also be obtained.
3. Hard and wear-resistant
Carry out hard anodic oxidation to obtain a thick and hard Al2O3 film on the surface. This film not only has high hardness and thickness, but also low roughness. In sulfuric acid or oxalic acid solution, a hard and thick oxide film can also be obtained on aluminum products by anodizing. The porous thick oxide film can store lubricating oil, so it can be effectively applied to aluminum products that work under friction, such as the engine cylinders and pistons of automobiles and tractors after being anodized, which can greatly improve their wear resistance.
4. Insulating electrical layer
The oxide film obtained after anodization has a large resistance, so it has a certain effect on improving the electrical insulation of some products. Anodization can be used to prepare the dielectric layer of the capacitor, or aluminum oxide can be used to prepare the surface for insulation. Floor.
5. Spray paint bottom layer
The porosity and good adsorption capacity of the anodic oxide film can be used as the bottom layer of spray paint and organic film, so that the paint film and organic film can be firmly combined with the product and increase the corrosion resistance.
6. Electroplating bottom layer
Before the aluminum products are electroplated, the bottom layer must be applied to them in advance, and then electroplating can be carried out. There are many methods for applying the bottom layer on the surface of the substrate. In addition to electro-galvanizing, electroless nickel plating, and zinc immersion, anodizing is also one of the important methods.