CN110184509A

CN110184509A - A kind of aluminium alloy and its product haveing excellent performance

Info

Publication number: CN110184509A
Application number: CN201910607167.7A
Authority: CN
Inventors: 吕崇新
Original assignee: Shenzhen Wanjia Interactive Technology Co Ltd
Current assignee: Foshan Gaodun Metal Co.,Ltd.
Priority date: 2019-07-06
Filing date: 2019-07-06
Publication date: 2019-08-30
Anticipated expiration: 2039-07-06
Also published as: CN110184509B

Abstract

The present invention provides a kind of aluminium alloy with Good All-around Property, based on Al-Mg-Si alloy, and its aluminum alloy plate materials being prepared.In the Al-Mg-Si-type aluminum alloy, containing being calculated with mass percentage, 1.0-1.5%Mg, 3.5-4.0%Si, 0.3-0.5%Cu, 0.4-1.0%Fe, 0.05-0.20%Mn, 0.20-0.30%Li, surplus are Al and inevitable impurity.Al-Mg-Si-type aluminum alloy in the present invention has excellent mechanical performance, especially elevated temperature strength performance, there is excellent formability and low-temperature bake hardening capacity simultaneously, be particularly suitable for application as motor vehicle body construction materials'use by the aluminum alloy plate materials that it is prepared.

Description

A kind of aluminium alloy and its product haveing excellent performance

Technical field

The present invention relates to the technical fields of alloy, and in particular to a kind of aluminium alloy, it is especially a kind of with excellent comprehensive Can, aluminium alloy based on Al-Mg-Si alloy, and its aluminum alloy plate materials being prepared.

Background technique

In recent years, since people are for the pay attention to day by day of the environmental protection problems such as exhaust gas discharge, and can not be again to reducing The continuous demand of raw energy consumption, also proposed increasingly higher demands for the car body lightweight of the means of transports such as motor vehicle.

And in the building material for including the body of motor vehicle such as bonnet, car door, roof, lighter (the about dense steel plate of quality The 1/3 of degree) forming property and the excellent aluminum alloy materials of baking and hardening performance use it is swift and violent increase, gradually instead of it is previous Directly lead steel to be used.

In existing numerous aluminum alloy materials, 6000 line aluminium alloys (i.e. JIS6000 line aluminium alloy, Al-Mg-Si class) with Magnesium and silicon are necessary alloying element, by the way that Mg is precipitated₂Si has small density, specific strength and specific stiffness as main hardening constituent The advantages that height, good impact resistance, corrosion resistance are high and thermal diffusivity is good, the aluminium alloy plate being prepared be especially suited as thin-walled and The motor vehicle body construction material high to intensity requirement is at present in the most widely used aluminium alloy of automotive field.Meanwhile The waste material of 6000 line aluminium alloy products is easy to obtain again after melting during recycling, since alloying element is few 6000 line aluminium alloy material ingot bars, cycling and reutilization are also splendid.

It above-mentioned excellent performance and is widely applied although 6000 line aluminium alloys have, still has and some it is to be difficult to Satisfied defect: although for example, the high ductility of 6000 line aluminium alloy tensile strength of conventional High Intensity is insufficient, bending etc. adds The problem of working hour is easy to produce crackle or even cracks；For example, the difference of the cross sectional shape of the aluminium alloy based on extrusion molding, thickness etc. It is different, cause the cooling velocity at each position in section to generate uneven and deform, so that accuracy to size is deteriorated and aluminium alloy Sheet become difficult, etc..

Wide application prospect and existing above-mentioned problems just because of 6000 line aluminium alloys, people are directed to 6000 Line aluminium alloy has carried out a large amount of research, to develop a kind of more excellent Al-Mg-Si-type aluminum alloy of comprehensive performance.

Summary of the invention

The purpose of the present invention is to provide a kind of Al-Mg-Si-type aluminum alloys of excellent combination property, to overcome existing skill The shortcomings that art and deficiency.

To achieve the above object, the present invention provides a kind of Al-Mg-Si-type aluminum alloy with excellent comprehensive performance, It is characterized by: in the Al-Mg-Si-type aluminum alloy, containing being calculated with mass percentage, 1.0-1.5%Mg, 3.5- 4.0%Si, 0.3-0.5%Cu, 0.4-1.0%Fe, 0.05-0.20%Mn, 0.20-0.30%Li, surplus are Al and can not keep away The impurity exempted from.

It is further preferred that mentioned component content meets 2.0≤Si_{It is extra}/(Cu+Fe)≤3.5。

It is further preferred that mentioned component content meets 2.2≤Si_{It is extra}/(Cu+Fe)≤3.0。

It is further preferred that mentioned component content meets Mn/Fe≤0.25.

It is further preferred that in the Al-Mg-Si-type aluminum alloy, containing being calculated with mass percentage, 1.5%Mg, 4.0%Si, 0.5%Cu, 0.9%Fe, 0.20%Mn, 0.25%Li, surplus are Al and inevitable impurity.

The present invention also provides a kind of aluminum alloy plate materials with excellent properties, by aforementioned Al-Mg-Si-type aluminum alloy system It is standby to obtain.

It is further preferred that the aluminum alloy plate materials are prepared by following step:

1) raw metal of Al-Mg-Si-type aluminum alloy is provided；

2) by raw metal heating melting, and fused raw material is poured by double-roller rolling equipment；

3) homogenize process is carried out to the plate after casting；

4) hot rolling, reduction ratio >=80% are carried out to the plate after homogenize process；

5) just cold rolling, reduction ratio >=30% are carried out to the plate after hot rolling；

6) it anneals to the plate after first cold rolling；

7) to annealing or plate carry out whole cold rolling so that total reduction >=60% after cold rolling twice；

8) it is heat-treated again after carrying out solution treatment to the plate of whole cold rolling.

It is further preferred that mechanical properties >=400MPa of the aluminum alloy plate materials, elongation percentage >=15%, high temperature are drawn Stretch intensity >=120MPa, coating baking hardening rear surface hardness >=135HV.

Compared with existing Al-Mg-Si-type aluminum alloy, the Al-Mg-Si-type aluminum alloy in the present invention has excellent mechanicalness Energy, especially elevated temperature strength performance, while there is excellent formability and low-temperature bake hardening capacity, the aluminium being prepared by it Sheet alloy is particularly suitable for application as motor vehicle body construction materials'use.

Specific embodiment

Embodiment 1

The Al-Mg-Si-type aluminum alloy plate of excellent combination property in the present invention is prepared via a method which:

After weighing each raw material in the specific ratio in table 1,40 DEG C higher than liquidus temperature are heated the raw material to be melted Melt molten metal, due to containing the light-alloys elements such as more silicon and magnesium in the present invention, is sufficiently stirred during heating melting to obtain To uniformly mixed molten metal.

Then, by pouring metal melt to double-roller rolling equipment, liquid level is higher by cast gate 30mm, to guarantee to generate enough static pressure To the state of die casting melt between stabilizing roller, wherein double-roller rolling equipment is hollow copper roller, and hollow interior is connected with coolant liquid Body, to guarantee that molten metal is chilled to 650 DEG C hereinafter, why to guarantee in this way with the speed of 200 DEG C/s or more from melting temperature Chilling speed, be because ultra-fine intermetallic compound can be obtained, so as to effectively improve the high temperature of aluminum alloy plate materials Intensity.Meanwhile driving double roller with 70m/ points of rotation peripheral speed opposite direction rotating, and apply opposite pressure 1.8kN/mm to copper roller respectively (kN/mm indicates the pressure for being applied to copper roller divided by the thickness of copper roller), if roller speed, which does not reach requirement, is easy to cause casting process The increase loaded of middle double roller and the fluctuation of melt solidified layer thickness, but roller speed can not be too high, too it is high be easy to cause it is molten Body contacts uneven with roll surface, and applying certain opposite pressure can cooperate roller speed to rotate, to keep the shape in solidification portion Stablize, but pressure is excessive, will lead to the roughening of roll surface and then influences the smooth of steel slab surface.

Then, homogenize process is carried out to slab, heat preservation 15 is small after the plate after casting is specifically heated to 500 DEG C of temperature Shi Hou is cooled to 320 DEG C or less with 130 DEG C/h of cooling velocity.The temperature of homogenize process must assure that in block Alloying element is uniform, eliminates segregation, and makes Mg₂Si can be sufficiently dissolved.Meanwhile why must assure that enough cooling speed Degree, be prevent the compound of Mg-Si in cooling procedure generate be precipitated, agglutination, to influence subsequent deep drawn performance and low The performances such as warm baking hardening.The homogenize process time will also be guaranteed, to guarantee the second phase particles for causing formability to deteriorate Abundant solid solution, but too long homogenize process effect saturation and cause productive low and cost increase.

Then, the start rolling temperature at 420 DEG C carries out hot rolling treatment, hot rolling reduction ratio 90%.Start rolling temperature is too low so that plate Material resistance of deformation is excessively high and is difficult to effective hot rolling, and the compound that will lead to Mg-Si generates and is precipitated, is aggregated, to influence subsequent Deep drawn performance and low-temperature bake hardening etc. performances.But start rolling temperature can not be excessively high, otherwise can make course of hot rolling Middle grain coarsening.The too low meeting of hot rolling reduction ratio is so that the generation of Cube orientation is insufficient, and then influences the formabilities such as crimping processing Energy.Hot rolling reduction ratio can not be excessively high, need to guarantee enough thickness after plate hot rolling, with there are enough pressures of subsequent cold rolling Space.

Then, just cold rolling is carried out, the reduction ratio of first cold rolling is 40%.The first too low whole cold rolling that will lead to after annealing of cold rolling The excessive generation that lower rate is excessive and Cube is caused to be orientated, and then lead to the generation of plate anisotropy, lead to deep drawn reduced performance.

Then, made annealing treatment, keep the temperature 2 hours after the plate after first cold rolling is specifically heated to 480 DEG C, then with Furnace is cooling.The temperature of annealing must assure that abundant recrystallization, but can not be excessively high, thick to prevent crystal grain during retaining fire Change and the formabilities such as crimping processing is caused to be deteriorated.

Then, whole cold rolling is carried out, after whole cold rolling, the total reduction of cold rolling twice is 65%.Cold rolling total reduction it is enough It can guarantee the abundant generation of Cube orientation greatly.But total reduction also should not be too large, such as more than 70%, it will cause each to different The problem of property.

After whole cold rolling, solution treatment is carried out to plate, the plate after cold rolling is specifically heated to 530 DEG C of solution treatment After temperature, 5 hours are kept the temperature, solid solution temperature is too low or soaking time is insufficient, all solution treatment can be caused insufficient, but such as Fruit temperature is excessively high to may result in the problems such as eutectic dissolves；After plate merging salt bath equipment is then chilled to 170 DEG C, then keep the temperature 1.5 hours, it is air-cooled to room temperature, by being chilled to the temperature lower than solution treatment, solid solution element in parent phase is enabled to be in Saturation state, to promote that Mg can be formed in the subsequent aging strengthening model stage₂Chemical combination among the Mg-Si of the beneficial hardening constituent of Si class The formation of object relatively can inhibit other harmful Mg-Si intermetallic compounds to generate naturally.Then carry out at timeliness heat again Reason, after plate is specifically heated to 110 DEG C, heat preservation was air-cooled to room temperature after 7 hours, and aging temp is too low or the time is too short Words, will lead to solid solution element cannot sufficiently be precipitated to form Mg₂Si so that strength reduction, and temperature is excessively high or the time too long then It will lead to extension property deficiency.

The Al-Mg-Si-type aluminum alloy composition proportion of the present invention of table 1

Serial number	Mg	Si	Cu	Fe	Mn	Li	Al	Si_{It is remaining}/(Cu+Fe)	Mn/Fe
										1	1.2	3.7	0.4	0.5	0.10	0.25	Surplus	3.3	0.20
2	1.5	4.0	0.5	0.9	0.20	0.25	Surplus	2.2	0.22
										3	1.0	3.5	0.3	0.8	0.10	0.30	Surplus	2.6	0.13
1#	2.0	4.0	0.4	0.8	0.15	0.25	Surplus	2.4	0.18
										2#	1.3	4.5	0.5	0.7	0.15	0.27	Surplus	3.1	0.21
3#	1.5	3.6	0.1	1.0	0.20	0.28	Surplus	2.5	0.20
										4#	1.4	4.0	0.3	1.3	0.20	0.25	Surplus	2.0	0.15
5#	1.5	4.0	0.4	0.7	0.05	0.23	Surplus	2.8	0.07
										6#	1.2	3.8	0.4	0.8	0.14	0.15	Surplus	2.6	0.17
7#	1.1	3.8	0.3	0.4	0.10	0.24	Surplus	4.5	0.25
										8#	1.2	3.6	0.4	0.7	0.20	0.28	Surplus	2.6	0.28

In embodiment 2-3 and comparative example 1#-8#, the ingredient of Al-Mg-Si-type aluminum alloy is adjusted, specific ingredient For proportion referring to table 1, the conditions such as remaining processing step, parameter are same as Example 1.

Mechanical properties, elongation percentage, drawing by high temperature have been carried out to the board product of embodiment 1-3 and comparative example 1#-8# The test of intensity (350 DEG C) and coating baking hardening performance.Wherein, mechanical properties, elongation percentage, high temperature tensile strength (350 DEG C) measured according to national standard；Coating baking hardening performance is to keep the temperature 30 minutes after plate to be heated to 140 DEG C to simulate The maintenance hardness of plate surface is then tested in the processing of coating baking.Obtained performance parameter is tested referring specifically to table 2.

The performance of the Al-Mg-Si-type aluminum alloy of the present invention of table 2

In the present invention, silicon addition and Mg are the main alloy elements of Al-Mg-Si-type aluminum alloy, are capable of forming β phase Mg-Si compound Mg₂Si, thus by being heat-treated effectively precipitation and playing invigoration effect to alloy, meanwhile, in Si and Mg shape At Mg₂Remaining Si solid solution is finally precipitated again in the base after Si, further can play invigoration effect to aluminium alloy, in order to Realize above-mentioned effect, enough β phases cannot be precipitated in the content of Si very little, while it is significant to will lead to subsequent baking and hardening performance Decline, extension are also deteriorated, and suitable Si can increase fluidity of molten to improve the casting character of alloy melt；But Si's Content can not be excessively high, the coarsening that cyrystal boundary segregation and crystal grain otherwise can be made to be precipitated, so that ductility and formability It can be deteriorated, meanwhile, the uniformity that excessive Si content will lead to melt alloy distribution is difficult to realize.

As described above, alloying element Mg mainly forms hardening constituent with Si, in order to obtain enough hardening constituents, the content of Mg It cannot be too low；But if the too high levels of Mg, it will be unable to obtain extra Si and be formed by additional strengthening effect, while Mg contains It measures the excessively high component segregation for also easily causing alloy melt and influences casting effect and properties of product.

Alloying element cu can form compound with Si assortment, to avoid embrittlement caused by the cyrystal boundary segregation of Si, in turn Promote the intensity and baking and hardening performance of alloy, moreover it is possible to improve the corrosion resistance and high temperature resistance of alloy；But the content of Cu Also unsuitable excessively high, it otherwise will lead to the deterioration such as corrosion resistance instead.

Alloying element Fe can play the role of solution strengthening, while Fe can play crystal grain refinement, to mention The mechanical performances such as the tensile strength of high alloy, and the increase of the crystal grain quantity as caused by crystal grain refinement, can effectively inhibit Extra Si is caused by the segregation of crystal boundary the problems such as embrittlement of grain boundaries, and in order to play above-mentioned effect, the content of Fe cannot be too low； But since Fe is easy to generate intermetallic compound with Al to reduce the plastic deformation ability of aluminium alloy, content is also unsuitable It is excessively high.

Alloying element Mn has certain solution strengthening effect, simultaneously because being capable of forming Al-Mn dispersed particle and playing Inhibit grain coarsening, to achieve the purpose that crystal grain refinement；The spherical precipitation that can also promote Fe-Al compound simultaneously, to keep away Exempt from the adverse effect that Fe-Al compound generates processing moulding；But the content of Mn is also unsuitable excessive, otherwise can cause instead thick The precipitation of big crystal and then the deterioration for leading to processing performance, and excessive Mn can also make melt solidus temperature increase, So that casting temperature increases and increases production cost and reduce production efficiency.

Alloying element Li can be during cure process be roasted in coating, hence it is evident that promotes β " to be mutually precipitated, thus subsequent It is changed into stable Mg in Natural Aging Process₂Si hardening constituent, therefore the addition of Li can significantly reduce coating barbecue hardening Treatment temperature and the performance of age-hardening, in order to play above-mentioned rental, the additive amount of Li cannot be too low；But the additive amount of Li Can not be excessively high, the excessively high elongation percentage that will lead to alloy and forming property decline, and melt can be made to have apparent ingredient inclined Analyse and influence the performance of cast article.

In addition, in order to prevent cyrystal boundary segregation caused by extra Si and embrittlement the problems such as, it is preferable that Si_{It is extra}/(Cu+Fe) ≤ 3.5, while to guarantee that extra Si plays enough invigoration effects, preferably 2.0≤Si_{It is extra}/ (Cu+Fe), enables to more in this way It while remaining Si plays invigoration effect, and is avoided that the various problems that extra Si may cause, is Si here_{It is extra}Refer to foundation Theory clearing, removing form Mg₂The remaining Si of Si.More preferably, 2.2≤Si_{It is extra}/(Cu+Fe)≤3.0。

In addition, although Mn can play the role of the spherical precipitation of certain promotion Fe-Al compound, excessive Mn Meeting so that Fe solid solution capacity wretched insufficiency, so that influencing Fe plays its effectiveness, especially for Si the segregation of crystal boundary inhibition Effect, therefore Mn/Fe≤0.25.

The aforementioned description to specific exemplary embodiment of the invention is in order to illustrate and illustration purpose.These descriptions It is not wishing to limit the invention to disclosed precise forms, and it will be apparent that according to the above instruction, can much be changed And variation.The purpose of selecting and describing the exemplary embodiment is that explaining specific principle of the invention and its actually answering With so that those skilled in the art can be realized and utilize a variety of different exemplary implementation schemes of the invention and Various chooses and changes.The scope of the present invention is intended to be limited by claims and its equivalents.

Claims

1. a kind of Al-Mg-Si-type aluminum alloy with excellent comprehensive performance, it is characterised in that: Al-Mg-Si system aluminium closes Jin Zhong, containing being calculated with mass percentage, 1.0-1.5%Mg, 3.5-4.0%Si, 0.3-0.5%Cu, 0.4-1.0%Fe, 0.05-0.20%Mn, 0.20-0.30%Li, surplus are Al and inevitable impurity.

2. Al-Mg-Si-type aluminum alloy according to claim 1, it is characterised in that: mentioned component content satisfaction 2.0≤ Si_{It is extra}/(Cu+Fe)≤3.5。

3. Al-Mg-Si-type aluminum alloy according to claim 2, it is characterised in that: mentioned component content satisfaction 2.2≤ Si_{It is extra}/(Cu+Fe)≤3.0。

4. Al-Mg-Si-type aluminum alloy according to claim 1, it is characterised in that: mentioned component content meet Mn/Fe≤ 0.25。

5. Al-Mg-Si-type aluminum alloy according to claim 1, it is characterised in that: in the Al-Mg-Si-type aluminum alloy, Containing being calculated with mass percentage, 1.5%Mg, 4.0%Si, 0.5%Cu, 0.9%Fe, 0.20%Mn, 0.25%Li, surplus For Al and inevitable impurity.

6. a kind of aluminum alloy plate materials with excellent properties, are prepared by aforementioned Al-Mg-Si-type aluminum alloy.

7. aluminum alloy plate materials according to claim 6, it is characterised in that: the aluminum alloy plate materials are prepared by following step It arrives:

1) raw metal of Al-Mg-Si-type aluminum alloy is provided；

3) homogenize process is carried out to the plate after casting；

6) it anneals to the plate after first cold rolling；

8. aluminum alloy plate materials according to claim 6 or 7, it is characterised in that: the room temperature tensile of the aluminum alloy plate materials is strong Degree >=400MPa, elongation percentage >=15%, high temperature tensile strength >=120MPa, coating baking hardening rear surface hardness >=135HV.