CN105316610A

CN105316610A - Treatment process of 2A90 aluminum alloy after tensile strength enhancement

Info

Publication number: CN105316610A
Application number: CN201410263576.7A
Authority: CN
Inventors: 王美
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-06-13
Filing date: 2014-06-13
Publication date: 2016-02-10

Abstract

The invention discloses a treatment process of 2A90 aluminum alloy after tensile strength enhancement. The 2A90 aluminum alloy includes the following components, by mass, 0.2% of a rare earth element Ce, 1.9% of an alloy element Cu and the balanced being pure aluminum ingots which include the following components, by mass, 99.29% of Al, 0.004% of B, 0.167% of Si, 0.271% of Fe, 0.055% of Mg, 0.041% of Cr, 0.027% of Ni, 0.033% of Ti and the balanced being impurities. The treatment process includes the steps of casting the alloy raw materials to obtain a circular rod; rolling the circular rod by means of a rolling machine; and finally performing low-temperature deformation aging treatment, wherein the rolling step includes 8-10 rolling times. In the invention, rolling pass is regulated to change microstructure of the material so that the material is effectively improved in mechanical performance and electricity conductive rate.

Description

The treatment process of a kind of 2A90 aluminium alloy after improving tensile strength

Technical field

The present invention relates to the treatment process after a kind of 2A90 aluminium alloy raising tensile strength, belong to alloy property technical field.

Background technology

Electrician's round bar is one of important foundation material of current electric wire, and its quality directly has influence on the quality of whole engineering or complete sets of products.In actual production, the tensile strength of round aluminum rod, contradiction often between electric conductivity and elongation, improve the tensile strength of aluminium bar, electric conductivity and elongation can decline, and when electric conductivity and elongation improve, intensity can reduce again.How to improve resistivity, and the relation of reasonable coordination tensile strength and elongation is the difficult problem waiting to solve.

The primary quality measure of 2A90 alloy product is specific conductivity and tensile strength.But because these two performance index are conflicting, be often difficult to meet, so will keep electroconductibility that material is higher and unit elongation, its intensity is often not enough simultaneously, but the strength of materials will be improved often can reduces its conductivity to a great extent.Therefore the good rolling technology studying higher specific conductivity and excellent mechanical property is its Chief technology.

Summary of the invention

The technical problem to be solved in the present invention: the treatment process after providing a kind of 2A90 aluminium alloy to improve tensile strength, can when small portion reduces 2A90 aluminium alloy electrician round bar resistivity, improve electric property and the mechanical property of electrician round bar, in order to solve 2A90 aluminium alloy improve tensile strength after electric conductivity sharply to decline a difficult problem.

Technical scheme of the present invention:

The treatment process of a kind of 2A90 aluminium alloy after improving tensile strength, described 2A90 aluminium alloy in the composition of massfraction is: the rare earth element ce of 0.2%, the alloying element cu of 1.9%, all the other are fine aluminium ingot, in fine aluminium ingot in the composition of massfraction be wherein: Al is 99.29%, B is 0.004%, Si be 0.167%, Fe is 0.271%, Mg is 0.055%, Cr is 0.041%, Ni be 0.027%, Ti is 0.033%, remaining as impurity, first alloy raw material is cast into rounding rod during process, then through roller mill rolling, finally carries out low temperature deformation ageing treatment.

Above-mentioned rolling number of processes is 8 ~ 10 times.

Beneficial effect of the present invention:

Compared with prior art, the present invention changes the microtexture of material by adjustment rolling pass, effectively can improve mechanical property and the electric conductivity of material, when rolling number of processes is 8 to 10 times, effect is comparatively obvious, especially when rolling 10 passage, its electric conductivity reaches 49.96(IACS) %, tensile strength reaches 238MPa, has well taken into account the balance of 2A90 Mechanical Properties of Aluminum Alloys and electric conductivity.

embodiment:

Embodiment:

The treatment process of 2A90 aluminium alloy after improving tensile strength, described 2A90 aluminium alloy in the composition of massfraction is: the rare earth element ce of 0.2%, the alloying element cu of 1.9%, all the other are fine aluminium ingot, in fine aluminium ingot in the composition of massfraction be wherein: Al is 99.29%, B be 0.004%, Si is 0.167%, Fe is 0.271%, Mg is 0.055%, Cr be 0.041%, Ni is 0.027%, Ti is 0.033%, remaining as impurity.

Due to rare earth element very active, directly add easy scaling loss, cause waste, increase cost, so must master alloy be mixed with, alloying element scaling loss can be reduced like this, guarantee the stable of alloying constituent.The preparation method of master alloy is: corundum crucible put into by fine aluminium, by well formula resistance furnace heat fused, after fine aluminium melts completely, alloyed metal (Ce and Cu) will be added broken, and dry and wrap with aluminium foil, adding in aluminium liquid when 750 DEG C, then constantly stir, until rare earth metal fragment fuses into completely, then at 800 DEG C ± 10 DEG C insulation about 2h, finally pour into mould for subsequent use.Rare earth element scaling loss will control about 1 ~ 3%, and the add-on thus in experiment can see actual content as, is finally prepared into massfraction w(Ce respectively)=Al-Ce the master alloy of 7.5% and massfraction w(Cu)=Al-Cu the master alloy of 15%.

Then cast, concrete casting process is: the aluminium ingot raw material calculating ratio is added in crucible and puts well formula resistance furnace into and heat to 780 DEG C ~ 800 DEG C, until completely melted, remove the bits on aluminium liquid surface, after reheating 780 DEG C ~ 800 DEG C, add in aluminium liquid with the load weighted master alloy of the thin parcel of aluminium, add rear titanium alloy bar and stir, churning time is 3min ~ 5min; Stirring makes it melt completely and is built by well formula resistance bell after mixing, make temperature recovery to smelting temperature about 800 DEG C, the floating foreign material in surface are removed, the cylinder sample of to be finally cast into diameter of phi be 12mm and diameter of phi to be 17mm, length L be 120mm after insulation several minutes.While insulation, need mould to carry out preheating at about 400 DEG C.Preheating mainly in order to reduce the temperature difference of aluminium liquid and mold wall, thus improves the cavity filling ability of aluminium liquid ^[9].After preheating completes, taking-up mould is cast at once, will have certain casting rate and pouring temperature during casting, ensures that aluminium liquid has good mobility and cavity filling ability.Be also noted that drainage during casting, prevent aluminium liquid from gushing out from crucible, be not cast in mould, the waste of aluminium liquid so both can have been avoided to ensure safety.

Choose above-mentioned in 10 diameters of having cast be the 2A90 aluminium alloy of 12mm, every 5 is one group, carries out the rolling of 1,2,3,4,5 passages respectively, then will wherein one group carry out low temperature deformation timeliness; Every 5 of the 2A90 aluminium alloy being 17mm by 10 remaining diameters is again divided into one group, carries out the rolling of 6,7,8,9,10 passages respectively, finally by wherein one group carry out above-mentioned aging technique.Then need the part steel certificate that has more at sample two ends to cut away, ensure during cutting that cross section is vertical with specimen surface as much as possible, and cutting sample cloth wraps up, avoid producing catcher mark because fixture holds too tight during cutting; Cutting speed in feet per minute is also unsuitable too fast, avoids as far as possible because fricative heat during cutting makes the too high oxidation that causes of specimen temperature or timeliness.In addition due to the reason of rolling cause rough, so must polish smooth with flint paper, then use 0 ~ No. 5 sand paper to polish successively.Dry up with blower again after finally rinsing well with clear water.

Adopt QJ57 Kelvin double bridge to measure sample resistance, through calculating the electric conductivity of the 2A90 aluminium alloy of element different, result is as following table 1:

The rolling of the different passage of table 1 is on the impact of electric conductivity

Tab.4.1Theeffectofdifferentrollingpassesonelectricalconductivity

Rolling pass	0	1	2	3	4	5	6	7	8	9	10
												IACS%	51.57	51.95	52.15	51.6	51.31	50.9	50.8	50.4	50.17	50.1	49.96

Instron-8501 material stretch test machine is adopted the sample of different content to be carried out to the detection of mechanical property.The tensile strength of main measurement sample.Its measuring result is as shown in table 2 below:

The rolling of the different passage of table 2 is on the impact of tensile strength

Tab.4.2Theeffectofdifferentrollingpassesontensilestrength

Rolling pass	0	1	2	3	4	5	6	7	8	9	10
												Tensile strength MPa	132	172	188	196	200	205	210	217	225	229	238

The experimentally result of phenomenon and test analysis, can draw following several conclusions: 1, along with the increase of rolling pass, and the electric conductivity of alloy declines; 2, along with the increase of rolling pass, the tensile strength of alloy improves; 3, after rolling 10 passage, electric conductivity reaches 49.96%, and tensile strength reaches 238MPa.

Claims

1. the treatment process of a 2A90 aluminium alloy after improving tensile strength, it is characterized in that: described 2A90 aluminium alloy in the composition of massfraction is: the rare earth element ce of 0.2%, the alloying element cu of 1.9%, all the other are fine aluminium ingot, in fine aluminium ingot in the composition of massfraction be wherein: Al is 99.29%, B is 0.004%, Si is 0.167%, Fe is 0.271%, Mg is 0.055%, Cr is 0.041%, Ni is 0.027%, Ti is 0.033%, remaining as impurity, first alloy raw material is cast into rounding rod during process, again through roller mill rolling, finally carry out low temperature deformation ageing treatment.

2. the treatment process of a kind of 2A90 aluminium alloy according to claim 1 after improving tensile strength, is characterized in that: described rolling number of processes is 8 ~ 10 times.

3. the treatment process of a kind of 2A90 aluminium alloy according to claim 1 after improving tensile strength, is characterized in that: described rolling number of processes is 10 times.