CN102354732A - Manufacture process of automobile power battery enclosure - Google Patents

Abstract

The invention provides a manufacture process of an automobile power battery enclosure, which comprises the following main steps of: (1) manufacturing aluminum alloy for the automobile power battery enclosure, wherein the aluminum alloy comprises the following components by weight percent: 0.10%<Si<0.60%, 0.40%<Fe<0.70%, 0.05%<Cu<0.20%, Mg<0.05%, 1.05%<Mn<1.25%, 0.15%<RE<0.40%, and 0.05<Ti<0.1, each of other elements is at most 0.05%, the total content of other elements is at most 0.15%, and the balance is aluminum; and (2) smelting the aluminum alloy proportioned by the step (1), casting the smelted aluminum alloy into a billet, and then sequentially carrying out four processes of homogenization, hot extrusion, heat treatment as well as punching and drawing on the billet to manufacture the automobile power battery enclosure. The automobile power battery enclosure manufactured through the process has excellent corrosion resistance, favorable high temperature creep property, and excellent punching-ironing processability and laser welding property, and is suitable for a square-shaped or box-shaped lithium ion battery case.

Description

A kind of manufacturing process of automobile power cell shell

Technical field

The present invention relates to the technical field of battery case manufacturing process, specifically be meant a kind of manufacturing process of automobile power cell shell.

Background technology

Environmental pollution and energy crisis have caused the extensive concern of countries in the world.At present, automobile approximately consumes 45% of crude output, and discharges a large amount of greenhouse gas CO2, also contains other dusty gass such as SO2 and NOX in the vehicle exhaust.Exploitation electric automobile (EV) has become the common eager task of approving in countries in the world, and the government north gate of a lot of automobile manufacturing companies, battery manufacturer, what various countries of chemical reagents corporation has been dropped into substantial contribution and manpower, quickens the research and development of EV.

In the existing battery that uses, the capacity density and the energy density of lithium ion battery are higher, are acknowledged as electrokinetic cell the most likely; But also there are some technical bottlenecks in lithium ion battery itself, it is widely used in automobile is restricted.These technical bottlenecks comprise: cost is high, the life-span is limited (generally require 10～15a), low temperature (20～-30 ℃) performance is bad and the potential safety hazard of battery itself.

Lithium battery was the production of China nearly ten years, and its sheathing material is a stainless steel at first, just progressively used aluminium alloy in several years up to date instead.Than stainless steel; Aluminium alloy has mechanical performance such as ductility preferably; Be prone to process the flat square container of an end back cover through deep-drawing deformation; The more important thing is its light weight; Characteristics such as good corrosion resistance, proper intensity, high-cooling property, reclaiming performance, explosion-proof performance are good; Each related scientific research unit, manufacturing enterprise all try to be the first and study and produce aluminium alloy battery shell; Deficiency for fear of knowhow and technology; Produce a complete aluminium alloy battery shell; Not only equipment needed thereby, manpower are many, and output also is restricted.Its punching out operation is many, punching out, ironing complex process, and the quality of punching press, ironing performance is relevant with material property and moulding process, the performance of material is one of extremely important factor of distortion success or not.

Summary of the invention

The objective of the invention is to overcome the deficiency of prior art; A kind of manufacturing process of automobile power cell shell is provided; Go out to have excellent corrosion resistance and good high-temperature croop property, good punching press-ironing processability and laser welding property through this explained hereafter, be suitable for square, box-like lithium-ion battery shell.

For realizing above-mentioned purpose, the present invention provides a kind of manufacturing process of automobile power cell shell, and the key step of this technology is:

The aluminium alloy that step 1, manufacturing automobile power cell shell are used; This aluminium alloy is to form by following percentage by weight proportioning: 0.10%＜Si＜0.60%; 0.40%＜Fe＜0.70%; 0.05%＜Cu＜0.20%; Mg＜0.05%, 1.05%＜Mn＜1.25%, 0.15%＜RE＜0.40%; 0.05＜Ti＜0.1; Other elements are at most 0.05% for every kind, and total amount is at most 0.15%, and surplus is an aluminium;

Step 2, the aluminium alloy that at first proportioning in the step 1 is got are cast as billet after melting, and then after this billet passed through homogenizing, hot extrusion, heat treatment, four working procedure processing of punching out pull and stretch successively, process the automobile power cell shell.

The present invention is through adding certain amount of mixed rare earth, can be used as refining agent melt is had the effect of degasification, significantly reduces the pin hole rate in the tissue; The adding of rare earth also can reduce the content of impurity in the aluminium alloy, has strengthened alloying level, makes alloy structure fine and close; In aluminium alloy melt, add an amount of rare earth the aluminium alloy as-cast structure is had metamorphism, can form transitional compound R EFe with alloying elements such as Fe and Si ₂With RESi etc., effectively control the solid solubility of superfluous element.Along with the increase of rare earth element addition, intensity, the plasticity of aluminium alloy all increase.This mainly has benefited from rare earth element to strong precipitation strength effect of the rare earth compound of the improvement of alloy structure and disperse etc.Add rare earth element and can cause that crack initiation position and expansion approach change in the alloy fracture process, help the malleableize of alloy.With the increase of content of rare earth, tensile strength, hardness improve in the while aluminium alloy, and elongation slightly descends.This shows that follow the adding of rare earth, the mechanical performance of alloy has much improvement.

Embodiment

Below in conjunction with specific embodiment the present invention is further specified.

Present embodiment adopts traditional smelting process to prepare aluminium alloy, and specifically in two steps: be raw material with pure Al (purity reaches 99.70%), mishmetal La-Y at first, in the hollow electric induction furnace, carry out melting, iron mould casting prepares the Al-10RE intermediate alloy; Then pure Al is put into smelting furnace and carry out melting; Smelting temperature is 750 ℃; By the time after pure Al dissolves fully; In melt, add manganese agent (75%), chalybeate (75%); After stirring; Add the Al-10RE intermediate alloy again; Stir; In melt, feed inert gas refining degasification, skim; Cast at last; Adopt the semi-continuous casting method to process rare earth aluminium alloy circle ingot casting, process the automobile power cell aluminum alloy casing through homogenizing, hot extrusion, heat treatment, sawing, punching out pull and stretch again.Below be several preferred embodiment prescriptions:

Alloy formula is (percentage by weight) as follows

Numbering	Fe	Mn	RE	Cu
					1#	0.50	1.10	0	0.10
2#	0.50	1.10	0.10	0.10
					3#	0.50	1.10	0.15	0.10
4#	0.50	1.10	0.20	0.10
					5#	0.50	1.10	0.25	0.10
6#	0.50	1.10	0.30	0.10
					7#	0.50	1.10	0.35	0.10
8#	0.50	1.10	0.40	0.10
					9#	0.50	1.10	0.45	0.10
10#	0.50	1.10	0.50	0.10

Annotate:

(1) burn out rate is Al-3%, Si-1%, and intermediate alloy Al-10RE does not consider scaling loss;

(2) the Al-10RE intermediate alloy is represented: the percetage by weight that mishmetal RE accounts for (comprising La and Y) intermediate alloy is 10%.

The embodiment of the above only is the present invention's preferred embodiment, is not to limit practical range of the present invention with this, so the variation that all shapes according to the present invention, principle are done all should be encompassed in protection scope of the present invention.

Claims (1)

1. the manufacturing process of an automobile power cell shell is characterized in that, the key step of this technology is:

The aluminium alloy that step 1, manufacturing automobile power cell shell are used; This aluminium alloy is to form by following percentage by weight proportioning: 0.10%＜Si＜0.60%; 0.40%＜Fe＜0.70%; 0.05%＜Cu＜0.20%; Mg＜0.05%, 1.05%＜Mn＜1.25%, 0.15%＜RE＜0.40%; 0.05＜Ti＜0.1; Other elements are at most 0.05% for every kind, and total amount is at most 0.15%, and surplus is an aluminium;

Step 2, the aluminium alloy that at first proportioning in the step 1 is got are cast as billet after melting, and then after this billet passed through homogenizing, hot extrusion, heat treatment, four working procedure processing of punching out pull and stretch successively, process the automobile power cell shell.