CN107190184B - A kind of mirror-like anodic oxidation Aluminum Plate and Strip and preparation method thereof - Google Patents

Abstract

The invention discloses a kind of mirror-like anodic oxidation Aluminum Plate and Strip and preparation method thereof, ingredient percentage is：Si≤0.03%, Fe≤0.03%, Cu 0.03 ~ 0.08%, Mn 0.06 0.1%, Mg 4.0 5.0%, Zn 0.16 0.25%, Zr 0.05 ~ 0.08%, Ti 0.02 ~ 0.03%, surplus are Al and inevitable impurity；It is using aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot as raw material, through founding, hot rolling, cold rolling, heat treatment and etc. be made.Aluminum Plate and Strip of the present invention is after anodic oxidation through mild mechanical polishing grinding, it can reach the mirror effect of high reflecting rate, meet electronic product Logo and highlight the needs of appearance and metal material wish that glass appearance surface is made, the shortcomings that effectively overcoming traditional 5 line aluminium alloys plate face micropore is more, without mirror effect after anodic oxidation.

Description

A kind of mirror-like anodic oxidation Aluminum Plate and Strip and preparation method thereof

Technical field

The invention belongs to aluminum and aluminum alloy mateial preparation fields, and in particular to a kind of mirror-like anodic oxidation Aluminum Plate and Strip And preparation method thereof.

Background technology

In recent years, aluminium after anodic oxidation because have the characteristics that anti-fingerprint pollution, case hardness it is high, on phone housing It is widely used in a variety of applications, but the hand that shell is brilliant black minute surface is produced in the variation with people to aesthetic, especially iPhone7 Machine starts, and more and more mobile phone brands wish phone housing of the development and production similar to effect.But since tradition 5 is alloy through sun After the oxidation of pole, hexagonal columnar micropore complicated, that arrangement is unordered can be formed on anodic oxide coating, and growth thickness is uneven, makes gold Belong to the anode surface of shell there are uneven phenomenon, surface roughness is larger, is influencing the different situation of light refraction angle It finally cannot get the effect of minute surface when visually observing down.

So far, the research for making it have mirror effect through anodic oxidation to aluminium is less, and proposes by controlling aluminium Compound in plate base and finish to gauge grain size realize that optimization region of the optimization aluminium after anodic oxidation be heterochromatic or anodic oxidation The uniformity of film it is more, even if the interface of aluminum substrate and anode oxide film can not be allowed flat in this way, good region is heterochromatic Directly, the anode oxide film hexagonal prism high-sequential, the thickness that are formed on this interface can not be allowed uniform, cause product surface cannot Mirror effect is presented.Primary handset brand manufacturers is using the aluminum products after anodic oxidation as handset shell and is adding in native land When work is mirror effect or highlighted LOGO, Chinese wax, colored varnish etc. need to also be used to block what anodic oxidation was formed after anodic oxidation Hexagonal prism micropore, then surface polishing grinding is carried out, to reduce surface roughness, achieve the effect that minute surface.

Invention content

The purpose of the present invention is to provide a kind of mirror-like anodic oxidation Aluminum Plate and Strips and preparation method thereof, in anode It can be in mirror effect to aoxidize rear surface, effectively overcome that traditional 5 line aluminium alloys plate face micropore after anodic oxidation is more, is imitated without minute surface The shortcomings that fruit.

To achieve the above object, the present invention adopts the following technical scheme that：

A kind of mirror-like anodic oxidation Aluminum Plate and Strip, ingredient percentage are：Si≤0.03%, Fe ≤ 0.03%, Cu 0.03 ~ 0.08%, Mn 0.06-0.1%, Mg 4.0-5.0%, Zn 0.16-0.25%, Zr 0.05 ~ 0.08%, Ti 0.02 ~ 0.03%, remaining is Al and inevitable impurity.

The mirror-like anodic oxidation with Aluminum Plate and Strip be using aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot as raw material, through founding, Hot rolling, cold rolling, heat treatment and etc. be made；Preparation method includes the following steps：

（1）Aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot carry out dispensing after smelting furnace melts respectively, then through semicontinuous casting Make obtained ingot casting；

（2）Ingot casting is sent into heating furnace behind sawing, milling face, is warming up to 440 ~ 450 DEG C with the rate of≤20 DEG C/h, heat preservation 16 ~ 40h avoids low melting point phase burning, is then brought rapidly up to 530 ~ 550 DEG C, keeps the temperature 1 ~ 12h, allows Zr to be fully dissolved, to make The coarse compound formed in casting process is fully spread uniformly, then is cooled to 450 ~ 480 DEG C, hot rolling of coming out of the stove, hot rolling finish to gauge temperature Degree is 250 ~ 350 DEG C, and hot rolled thickness is 3.0 ~ 10.0mm；

（3）The cold rolling that coiled material after hot rolling is carried out to 50-80%, is then warming up to 360-460 with the rate of >=60 DEG C/h DEG C, heat preservation 2-6h carries out intermediate annealing（It is preferred that continuous annealing furnace produces）, to avoid slow heating cause crystal grain grow up and part Coarse grains, then it is cold rolled to finished product thickness, cold rolling reduction ratio is 40 ~ 80%, again through drawing after 150-280 DEG C of finished products Curved aligning finished product.

After stretch-bending straightening of the present invention the tensile strength of gained Aluminum Plate and Strip be 240 ~ 300MPa, yield strength be 205 ~ 235MPa（Case hardness HV75 ~ 81）, meet the demand that cracking does not occur for corner after pressing and bending deforms.

Applicant it has been investigated that, crystal grain is orientated different, the direction of growth of hexagonal prism micropore on aluminium alloy anode oxide layer It is different with speed；Correspondingly, the isometric property of crystal grain is higher, and orientation more reaches unanimity.As arbitrary 1mm²Grain size in range When difference is no more than 3 μm, grain-oriented randomness is minimum, and the orientation consistency of micropore is very strong after film forming；And add in the alloy Add a certain amount of Zn, initial film forming speed when anodic oxidation increases, and can be further reduced crystal grain and be orientated the shadow being orientated to micropore It rings, i.e., when carrying out anodic oxidation with this condition, the interface of aluminum substrate and anode oxide film will tend to be straight.Meanwhile aluminium alloy In intermetallic compound size can influence current density and Al ion concentrations, and then influence the uniform of anodic oxidation micropore size The thickness of property and oxidation film is beneficial to the homoepitaxial of anode oxide film if effectively controlling compound size.

The present invention is using aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot as raw material, after founding, hot rolling, cold rolling and necessary heat treatment In the Aluminum Plate and Strip of production, intermetallic compound maximum length is no more than 6 μm, crystal grain after intermediate annealing in etc. shaft-like, big It is small to be no more than 30 μm, and arbitrary 1mm²Difference in size≤3 μm of arbitrary crystal grain in range make it carry out anodic oxidation When, it is ensured that oxide thickness is uniformly and oxidation micropore is High ordering, to which mirror effect be presented；And it is found through experiment that, Under the same terms, even if controlling intermetallic compound size to 6 μm hereinafter, 5 be alloy cannot still be formed after anodic oxidation Anode oxide film with mirror effect.

Gained mirror-like anodic oxidation of the invention with Aluminum Plate and Strip compared with traditional 5 systems, in chemical composition, casting, hot rolling Improved in heating cycle and cold rolling processing technology, make its with general 6063T6 case hardnesses, meet Pressing Deformation It is indehiscent simultaneously, also have the characteristics that aluminum substrate and interfacial oxide film are straight, anode oxide film is in homogeneous thickness, to make its warp It is the mirror effect not available for alloy that gained anode oxide film, which has general 5, after anodic oxidation.

Specific implementation mode

A kind of mirror-like anodic oxidation Aluminum Plate and Strip, ingredient percentage are：Si≤0.03%, Fe ≤ 0.03%, Cu 0.03 ~ 0.08%, Mn 0.06-0.1%, Mg 4.0-5.0%, Zn 0.16-0.25%, Zr 0.05 ~ 0.08%, Ti 0.02 ~ 0.03%, surplus is Al and inevitable impurity（The content of each impurity is no more than 0.03%）；Gold in its aluminium alloy Shaft-like, the sizes such as compound maximum length is no more than 6 μm between category, and the crystal grain after intermediate annealing is in are no more than 30 μm, and arbitrary 1mm²Difference in size≤3 μm of arbitrary crystal grain in range, and 205 ~ 235MPa of yield strength can be met in mechanical property, it rushes The demand that compressive strain is not cracked.

The reasons why carrying out numerical definiteness to the content of each ingredient below is illustrated：

Mg：Mg in alloy is addition element necessary to ensureing sheet alloy intensity, if content is less than 4.0%, finished product Yield strength index cannot meet, if content is more than 5.0%, the diffusion of Fe, Si, Cu, Mn are on the one hand influenced in fusion-casting process, So that the phase containing Fe in solidification is formed coarse compound, and then influence finished anode oxide thickness uniformity, is unfavorable for finished product and obtains The anodized surface of low roughness is obtained, another aspect Mg contents, which increase, will improve aluminium intensity, cause rolling difficulty；

Fe：Fe is conducive to inhibit the roughening of heat treatment process crystal grain, and provides partial reinforment effect, but Fe contents are more than When 0.03%, β can be formed（AlFeSi）Phase even promotes AL when more than 0.2%₆Fe phases increase, such compound in rodlike or Strip, it is non-breakable in follow-up rolling deformation process, and hinder the formation of oxidation film, aggravation region different in anode oxidation process Color.

Si：Si in alloy is mainly impurity, and the quantity and size of the content compound of the composition are directly proportional, make anodic oxygen Surface after change is muddy, therefore need to be strict controlled within 0.03%.

Ti：Ti is the essential element for inhibiting cast sturcture's roughening, and preferred content 0.025% can be formed thick when content is higher Large compound promotes forming region heterochromatic.

Cu、Mn：Cu, Mn are conducive to improve the intensity of material, and addition in a certain range can be dissolved into AlFe phases, Improve the structure of AlFe phases, the dissolving of compound when ingot homogenization high temperature section being promoted to keep the temperature；And when excessive addition Cu, it will be formed Al₂Cu compounds make oxidation film become muddy and no longer thoroughly white, need to be strict controlled in 0.08% or less.

Zn：Zn additive amounts are more than that the pore-forming efficiency of hexagonal prism micropore in anode oxidation process can be improved after 0.16%, are reduced The pore-forming efficiency difference caused by crystal grain is orientated difference, avoids micropore uneven thickness after subsequent growth, and additive amount is more than 0.25%, the corrosion resistance of oxidation film will be influenced, therefore 0.25% or less need to be strict controlled in.

Zr：A small amount of addition Zr is beneficial to improve recrystallization temperature, inhibits crystal grain to grow up, ensures the uniformity of crystal grain；And It when addition is more than 0.08%, will continue to improve recrystallization temperature, easily cause batch annealing process crystal grain uneven.

In order to make content of the present invention easily facilitate understanding, With reference to embodiment to of the present invention Technical solution is described further, but the present invention is not limited only to this.

Embodiment 1

A kind of mirror-like anodic oxidation Aluminum Plate and Strip, ingredient percentage are：Si 0.024%, Fe 0.025%, Cu 0.05%, Mn 0.07%, Mg 4.5%, Zn 0.18%, Zr 0.05%, Ti 0.023%, surplus are Al and can not keep away The impurity exempted from.

Preparation method includes the following steps：

（1）Aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot carry out dispensing after smelting furnace melts respectively, then through low liquid level half Ingot casting is made in continuously casting；

（2）Ingot casting is sent into heating furnace behind sawing, milling face, 440 DEG C is warming up to the rate of≤20 DEG C/h, keeps the temperature 40h, Then it is brought rapidly up to 550 DEG C, keeps the temperature 1h, then be cooled to 480 DEG C, hot rolling of coming out of the stove, hot rolling finishing temperature is 350 DEG C, and hot rolling is thick Degree is 8.0mm；

（3）Coiled material after hot rolling is carried out to 60% cold rolling, is then warming up to 400 DEG C with the rate of >=60 DEG C/h, keeps the temperature 2h Intermediate annealing is carried out, then is cold rolled to finished product thickness, cold rolling reduction ratio is 60%, is rectified again through stretch bending after 270 DEG C of finished products Straight finished product.

Gained aluminium alloy strips thickness 1.0mm, tensile strength 270MPa, yield strength 220MPa, elongation percentage 10.8%, Intermetallic compound maximum length contained by its inside is 5.6 μm；Sampling carries out analysis comparison to the crystal grain of longitudinal section after moderate heat, It is per 1mm²The difference in size of arbitrary crystal grain in range is 2.2 μm, and after surface is polished after anodic oxidation, finished product plate face is in mirror Face effect.

Embodiment 2

A kind of mirror-like anodic oxidation Aluminum Plate and Strip, ingredient percentage are：Si 0.02%, Fe 0.02%, Cu 0.03%, Mn 0.06%, Mg 4.0%, Zn 0.16%, Zr 0.06%, Ti 0.025%, surplus are Al and can not keep away The impurity exempted from.

Preparation method includes the following steps：

（1）Aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot carry out dispensing after smelting furnace melts respectively, then through low liquid level half Ingot casting is made in continuously casting；

（2）Ingot casting is sent into heating furnace behind sawing, milling face, 440 DEG C is warming up to the rate of≤20 DEG C/h, keeps the temperature 20h, Then it is brought rapidly up to 540 DEG C, keeps the temperature 3h, then be cooled to 460 DEG C, hot rolling of coming out of the stove, hot rolling finishing temperature is 300 DEG C, and hot rolling is thick Degree is 3.0mm；

（3）Coiled material after hot rolling is carried out to 80% cold rolling, is then warming up to 360 DEG C with the rate of >=60 DEG C/h, keeps the temperature 6h Intermediate annealing is carried out, then is cold rolled to finished product thickness, cold rolling reduction ratio is 40%, is rectified again through stretch bending after 150 DEG C of finished products Straight finished product.

Gained aluminium alloy strips thickness 0.36mm, tensile strength 240MPa, yield strength 205MPa, elongation percentage 12.8%, Intermetallic compound maximum length contained by its inside is 5.5 μm；Sampling carries out analysis comparison to the crystal grain of longitudinal section after moderate heat, It is per 1mm²The difference in size of arbitrary crystal grain in range is 2.7 μm, and after surface is polished after anodic oxidation, finished product plate face is in mirror Face effect.

Embodiment 3

A kind of mirror-like anodic oxidation Aluminum Plate and Strip, ingredient percentage are：Si 0.027%, Fe 0.027%, Cu 0.08%, Mn 0.1%, Mg 5.0%, Zn 0.25%, Zr 0.08%, Ti 0.028%, surplus are Al and can not keep away The impurity exempted from.

Preparation method includes the following steps：

（1）Aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot carry out dispensing after smelting furnace melts respectively, then through low liquid level half Ingot casting is made in continuously casting；

（1）Ingot casting is sent into heating furnace behind sawing, milling face, 450 DEG C is warming up to the rate of≤20 DEG C/h, keeps the temperature 16h, Then it is brought rapidly up to 530 DEG C, keeps the temperature 12h, then be cooled to 450 DEG C, hot rolling of coming out of the stove, hot rolling finishing temperature is 250 DEG C, and hot rolling is thick Degree is 10.0mm；

（3）Coiled material after hot rolling is carried out to 50% cold rolling, is then warming up to 460 DEG C with the rate of >=60 DEG C/h, keeps the temperature 2h Intermediate annealing is carried out, then is cold rolled to finished product thickness, cold rolling reduction ratio is 80%, is rectified again through stretch bending after 280 DEG C of finished products Straight finished product.

Gained aluminium alloy strips thickness 1.0mm, tensile strength 300MPa, yield strength 235MPa, elongation percentage 10.2%, Intermetallic compound maximum length contained by its inside is 5.3 μm；Sampling carries out analysis comparison to the crystal grain of longitudinal section after moderate heat, It is per 1mm²The difference in size of arbitrary crystal grain in range is 2.0 μm, and after surface is polished after anodic oxidation, finished product plate face is in mirror Face effect.

The foregoing is merely presently preferred embodiments of the present invention, all equivalent changes done according to scope of the present invention patent with Modification should all belong to the covering scope of the present invention.

Claims (3)

1. a kind of mirror-like anodic oxidation Aluminum Plate and Strip, it is characterised in that：Its ingredient percentage is：Si≤ 0.03%, Fe≤0.03%, Cu 0.03 ~ 0.08%, Mn 0.06-0.1%, Mg 4.0-5.0%, Zn 0.16-0.25%, Zr 0.05 ~ 0.08%, Ti 0.02 ~ 0.03%, surplus are Al and inevitable impurity；

The mirror-like anodic oxidation with Aluminum Plate and Strip be using aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot as raw material, through founding, hot rolling, Cold rolling, heat treatment are made；It specifically includes following steps：

（1）Aluminium ingot, aluminium intermediate alloy ingot, magnesium ingot carry out dispensing after smelting furnace melts respectively, then through semi-continuous casting system Obtain ingot casting；

（2）Ingot casting is sent into heating furnace behind sawing, milling face, 440 ~ 450 DEG C are warming up to the rate of≤20 DEG C/h, heat preservation 16 ~ Then 40h is brought rapidly up to 530 ~ 550 DEG C, keep the temperature 1 ~ 12h, then be cooled to 450 ~ 480 DEG C, hot rolling of coming out of the stove, hot rolling finishing temperature It it is 250 ~ 350 DEG C, hot rolled thickness is 3.0 ~ 10.0mm；

（3）Coiled material after hot rolling is subjected to intermediate annealing after the cold rolling of 50-80%, intermediate anneal temperature is 360-460 DEG C, Soaking time is 2-6h, is then cold rolled to finished product thickness, cold rolling reduction ratio is 40 ~ 80%, by 150-280 DEG C of finished products Afterwards again through stretch-bending straightening finished product.

2. mirror-like anodic oxidation Aluminum Plate and Strip according to claim 1, it is characterised in that：Step 1）Described partly connects Continuous casting is low liquid level semi-continuous casting.

3. mirror-like anodic oxidation Aluminum Plate and Strip according to claim 1, it is characterised in that：Step 3）When intermediate annealing The rate of heat addition be >=60 DEG C/h.