CN103407222A - Sheet metal of multi-layer structure - Google Patents

Abstract

The invention discloses a sheet metal of a multi-layer structure. The sheet metal is characterized by comprising four layers of metal layers which are parallelly distributed, the two outermost layers are made of nickel, the sum of the thicknesses of the two outermost layers does not exceed 30% of the total thickness of the sheet metal, and the two middle layers are made of stainless steel, copper or copper alloy and low-carbon steel according to a certain proportion.

Description

A kind of sheet metal of sandwich construction

Technical field

The present invention relates to a kind of sheet metal of sandwich construction, can save and substitute existing pure nickel band, paper tinsel, sheet material for a large amount of employings of industry institute such as the field of batteries such as NI-G, ni-mh, lithium ion, lighium polymer, assembled battery and electric tool, information communication, special lamps.Belong to metal-based layer-shaped technical field of composite materials.

Background technology

At present at inside lug, the brace of battery pack and the pin of PTC overflow protecting element of the field of batteries such as NI-G, ni-mh, lithium ion, lighium polymer, assembled battery, and need to adopt in a large number pure nickel band, paper tinsel, sheet material in the industries such as electric tool, information communication, special lamp electrovacuum element.Above-mentioned concrete application all has preferably mechanical performance and can resist multiple corrosive substance based on nickel, in calorifics, electricity and magnetics category, good performance is arranged all.

In the industry field of above-mentioned fast development, a large amount of pure nickels that use have partly driven the vigorous pace of global nickel demand, but the situation of critical shortage has appearred supplying in nickel market at present, and authority estimates that the nickel valency is by continuous rise.Britain international standard commodity research institution (CRU) prediction 2004 and global nickel supply gap in 2005 are respectively 3.3 ten thousand tons and 2.8 ten thousand tons.But meanwhile crisis has appearred in global nickel ore resource, new units increased in production is very limited.From China's situation, the same nickel of China is in great demand but nickel ore resource is very nervous.It is predicted, global nickel demand growth will be from China more than 70%.The nickel demand of predicting 2004,130,000 one 14 ten thousand tons of left and right, will reach 150,000 tons in 2005, and 2010 will be over 200,000 tons.But at present the nickel output of the self-produced raw material of China is only approximately 60,000 tons, and the short supply situation is also very serious.And limited can only the dependence of China's nickel storage level situation found raw material supply from outside, from 2000, China became the pure importer of former nickel, and the net importation amount continues strong growth.900,000,000 dollars, China's import nickel in 2003 and goods, increase by 110% on a year-on-year basis.

In the situation that nickel valency continuous rise and global nickel resources shortage are necessary the measure of practise economy with nickel, to reduce domestic and international market nickel valency, can reduce the foreign exchange expenditure for China, reduce domestic each relevant cost that uses the more industry of pure nickel.From external experience, phase in short supply U.S. of three nickel has all taked effectively to economize on the nickel measure: in " World War II " period, because nickel is in short supply, the U.S. drops to 50% by nickel austenite steel ratio in stainless steel production by common 80% left and right; After " Korean War " in 20th century, nickel resources is nervous once again, and the U.S. promotes the use of with copper for nickel; The nickel U.S. in period in short supply also actively took measures to reduce the nickel amount of using in 1989.At present, due to the China's economic fast development, the nickel resources shortage, also be necessary actively to take measures.Wherein, develop from the technical point of view the new function material that can substitute a large amount of pure nickel bands that use, paper tinsel, sheet and will have very important strategic importance and realistic meaning.The present invention takes full advantage of the combination advantage of composite material, can, in a large amount of saving pure nickel materials, realize that the very approaching even part of integral material characteristic performance, also in pure nickel band, paper tinsel, sheet, finally reaches a large amount of purposes that substitute.

At present in battery and other a large amount of industries of using pure nickel bands, sheet, paper tinsel, some joint nickel of having taked of each producer are mainly use plated nickel materials by the material technology both at home and abroad, and only a few has been used the compound nickel material that covers of rolling.Above-mentioned plated nickel material all is no more than three-layer metal, mainly contains nickel plated steel strip (comprising common nickel plated steel strip and infiltration type nickel plated steel strip), nickel plating copper strips, nickel plating stainless steel band etc. several.There are following very scabrous problems also so far in these plated nickel materials:

1) in necessary plating or chemical plating manufacture process, need to use and discharge the chemical substances such as a large amount of acid, alkali and environmental pollution is very serious, even adopted emission treatment, indirectly increased production cost.

2) nickel layer thickness of plated nickel material is generally between 0.3～6 μ m, and thicker nickel coating and substrate combinating strength can be more weak, and how many top layers all exist certain porosity (at least more than 2%), exist and cover nickel dam and easily peel off (bend if in process, needed be shaped or duty needs the sliding friction occasion) and the larger possibility of etched the matrix.

3) all there is the place that can differ greatly with the pure nickel wood property in each plated nickel material on performance.Nickel plated steel strip is because base layer is mild steel (low than pure nickel material electrical conductivity), the resistivity of integral material exceeds more than 40% than pure nickel, the same reason of the stainless resistivity of nickel plating exceeds pure nickel more than 6 times, these have all increased the internal resistance of battery greatly, are unfavorable for improving battery capacity and service life; Although and nickel plating copper strips resistivity is low than the pure nickel band, it is because matrix is copper, material monolithic intensity can not show a candle to the pure nickel band, has limited material in many application that intensity had to instructions for use.

Obtained at present saving pure nickel composite material prepared by the roll-bonding method of practical application, only had three layers composite metal Ni/Cu/Ni, still had equally above-mentioned 3) in the strength character problem of the nickel plating copper strips carried.

Summary of the invention

The object of the invention is to: the obvious weak point of avoiding wholly or in part the plated nickel material to exist, improve the compound trilaminate material design philosophy of covering the nickel material of rolling, provide a kind of new saving pure nickel for nickel composite metal band, paper tinsel, sheet.This composition metal takes full advantage of the combination advantage of multilayer material in composition metal, that adopts in a large number non-pure nickel saves the pure nickel material in a large number than cheap metal, when reducing costs, realize that the very approaching even part of integral material characteristic performance also is better than pure nickel band, paper tinsel, sheet, finally reaches a large amount of purposes that substitute.

Technical scheme of the present invention is achieved in that a kind of sheet metal of sandwich construction, it is characterized in that: comprise, the metal level of four layers of parallel distribution, the two-layer of outermost consists of nickel, its thickness sum is no more than 30% of described sheet metal gross thickness, and the two-layer of centre constituted by a certain percentage by stainless steel, copper or copper alloy, mild steel.

Improvement of the present invention is: for nickel composite metal band, sheet, paper tinsel, when the combination of layer and interlayer all adopted roll-bonding methods to manufacture, preferably two outermost aspects were basic equal proportion and the pure nickel that all accounts for finished product total thickness 5～15%.Group element material can be nickel, copper, stainless steel combination and nickel, copper, mild steel combination two large types, the order of composition material can be nickel/copper/stainless steel/copper/nickel, nickel/stainless steel/copper/stainless steel/nickel, nickel/copper/mild steel/copper/nickel, nickel/mild steel/copper/mild steel/four kinds, nickel, wherein nickel used is pure nickel (percentage by weight of Ni+Co is more than 99.0%), stainless steel is austenitic stainless steel or ferritic stainless steel, copper be in fine copper (the cupric percentage by weight is more than 99.50%), mild steel the phosphorus content percentage by weight below 0.12%.

When generation of the present invention nickel composite metal outermost nickel dam and time outer interlayer in conjunction with employing plating method (and other takes roll-bonding method between layers) time, institute's nickel coating thickness is about 0.3～6 μ m.

When generation of the present invention nickel composite metal intermediate layer (namely except two outermost thin nickel material layers) for mild steel (or stainless steel) and copper and while adopting the two-sided plated copper method of mild steel (or stainless steel) (other takes roll-bonding method between layers), institute's thickness of coated copper layer is about 0.3～6 μ m.

The invention has the advantages that the performance and the cost price characteristics that fully combine each constituent element metal, realized learning from other's strong points to offset one's weaknesses, reach the purpose of design that the very approaching even part of overall performance surpasses the pure nickel material.In invention, related nickel, stainless steel, copper, mild steel is the common metal material product used in a large number, and each Main Mechanical, corrosion resisting property, electrical property, relative price are listed in table 1.And the computing formula such as whole tensile strength for nickel composite metal, resistivity, price are as follows:

Tensile strength ${\mathrm{\σ}}_b-{\mathrm{\σ}}_b=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{t}_i{\mathrm{\σ}}_{\mathrm{bi}}$

Resistivity $\mathrm{\ρ}-\frac{1}{\mathrm{\ρ}}=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{t_i}{{\mathrm{\ρ}}_i}$

Price $P-P=\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{t}_i{P}_i$

Wherein

The bed thickness ratio summation that is each layer is 1.

Table 1 pure nickel and other non-nickel metallicity and price comparison

Annotate: 1) data in above table are reference value, with measured value, are as the criterion during actual design;

2) above-mentioned material is under full annealing state condition.

As can be seen from Table 1, in to the basic demand of pure nickel serviceability, each material (same state) tensile strength by high to Low order is in the ordinary course of things: stainless steel>nickel>mild steel>copper; Resistivity order from high to low is: stainless steel>mild steel>nickel>copper; Relative price order from high to low is: nickel>copper>stainless steel>mild steel; Copper, stainless corrosion resistance (refer to same environment that pure nickel uses in) are all better, and mild steel is by plated copper or nickel can better solve anti-corrosion problem on every side.The structure carried in invention of take is example.To exceed pure nickel many because the electric conductivity of copper and stainless intensity are all corresponding, and copper, stainless corrosion resistance meets most pure nickel bands, paper tinsel, the environment for use requirement of sheet, can analyze like this: as first in the two-layer compound certain thickness ratio Combination Design of copper/stainless steel, just can realize the electric conductivity of two layer composite structure integral body fully, intensity, the performances such as corrosion resistance are the very approaching pure nickel that even is better than all, now only need on the basis of said structure, superposeing, it is two outer for being any thickness ratio (certainly more Bao Yuehao but compound difficulty is also higher) but the design of the pure nickel that preferably equates again, can meet the performance requirement of alternative pure nickel (while because of two outermost layers, being pure nickel comprehensively, if can solve two skins, are surface state that non-pure nickel metal may bring, outward appearance, the problems such as welding), and the more important thing is that this design is because the non-nickel material of a large amount of employing in thickness proportion (being part by weight) has realized greatly saving the nickel material, the purpose reduced costs.Therefore key of the present invention is that by design, controlling each layer of composite material well is non-pure nickel metal thickness proportion between layers especially, just can realize that the very approaching even part of performance of integral material surpasses the purpose of design of pure nickel material.Its manufacture can be in the rolling for other kind composite material compound or plating or rolling compound+realize on the production line of plating, production cost is low and efficiency is high.

The specific embodiment

Embodiment 1:

Material for nickel composite metal consists of nickel/copper/stainless steel/copper/nickel four-layer structure, two outermost layer pure nickels 1 (percentage by weight of Ni+Co is more than 99.0%) account for the total thickness ratio and are 11.5% left and right, pure copper layer (the cupric percentage by weight is more than 99.50%) accounts for the total thickness ratio and is 11%, it is 55% that stainless steel layer (1Cr18Ni9 austenitic stainless steel) accounts for the total thickness ratio, and namely total thickness (weight) ratio of each constituent element is: outer nickel: copper: stainless steel=23: 22: 55.The material of design proves through Post Manufacturing Checkout like this, and the average resistivity of its integral material (annealed state) is 7.1 μ Ω .cm, and average tensile strength is 420MPa, percentage elongation >=30%, and all index all approaches fully and also partly is better than pure nickel.And through domestic certain well-known this example materials of battery manufacture station-service (cross sectional dimensions is 0.10*4) as lug, brace, carried out comprising the full test of soldering reliability, internal resistance, chemical property etc., lug and the brace of same its complete alternative former pure nickel of proof, and partial properties also is better than, and (particularly its internal resistance is less than 20m Ω, and be about 30m Ω with pure nickel), decrease material cost meanwhile.

Roll-bonding method is adopted in the manufacture of this material, can be disposable compound, can be also twice compound, take diffusion annealing heat treatment after compound, then repeat-rolling and intermediate softening annealing, finally make finished product.This process route maturation, production cost is low and efficiency is high.

Embodiment 2:

Material group for nickel composite metal is nickel/stainless steel/copper/nickel four-layer structure, two outermost layer pure nickels 1 (percentage by weight of Ni+Co is more than 99.0%) account for the total thickness ratio and are 11.5% left and right, stainless steel (1Cr18Ni9 austenitic stainless steel) accounts for the total thickness ratio and is 27.5%, and the total thickness ratio that accounts for of fine copper (the cupric percentage by weight is more than 99.50%) is 22%.The material of design is compared with example 1 like this, the total thickness proportion that does not change each group element material forms (outer nickel: stainless steel: copper=23: 55: 22), just inferior skin and intermediate layer group element material are changed, but its integral material (annealed state) is in full accord with exhausted most performance of embodiment 1, too fully near the pure nickel material property, the alternative pure nickel band of its finished product, paper tinsel, sheet.

Its manufacture process is similar to improves embodiment 1.

Claims (8)

1. the sheet metal of a sandwich construction, it is characterized in that: comprise, the metal level of four layers of parallel distribution, the two-layer of outermost consists of nickel, its thickness sum is no more than 30% of described sheet metal gross thickness, and the two-layer of centre constituted by a certain percentage by stainless steel, copper or copper alloy, mild steel.

2. sheet metal as claimed in claim 1, wherein, when layer and interlayer when all adopting roll-bonding methods to manufacture, two outermost aspects are equal proportion and the pure nickel that all accounts for finished product total thickness 5～15%.

3. sheet metal as claimed in claim 2, wherein, in nickel used, the percentage by weight of nickel element is more than 99.0%.

4. sheet metal as claimed in claim 2, wherein, described stainless steel is austenitic stainless steel or ferritic stainless steel.

5. sheet metal as claimed in claim 2, wherein, in described mild steel, the phosphorus content percentage by weight is below 0.12%.

6. by sheet metal claimed in claim 1, wherein, when plating method was adopted in the combination between outermost nickel dam and intermediate layer, institute's nickel coating thickness was 0.3～6 μ m.

7. sheet metal as claimed in claim 1, wherein, when intermediate layer is mild steel and copper and while adopting the two-sided plated copper method of mild steel, institute's thickness of coated copper layer is 0.3～6 μ m.

8. sheet metal as claimed in claim 1, wherein, when intermediate layer is stainless steel and copper and while adopting stainless steel double-sided plated copper method, institute's thickness of coated copper layer is 0.3～6 μ m.