JP2012210646A - Foil-shaped brazing filler metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brazing filler metal which is low in melting point and suitable for vacuum-brazing an aluminum-system metal, has a foil shape, and is excellent in flexibility.SOLUTION: The brazing filler metal is composed of, by mass, 10.0 to 24.5% of Cu, and 4.0 to 10.0% of Si, and its remaining part is composed of Al and inevitable impurities. The brazing filler metal uses a rapid-cooling coagulation foil body having a chemical composition in a range (including a boundary ) in which contents of Cu and Si are surrounded by a linear line which connects A-B-C-D-E-F-A in Fig.1, and the average thickness of the brazing filler metal is 15 to 100 μm.

Description

本発明はアルミニウム系金属（アルミニウムまたはアルミニウム合金）のろう付けに適した低融点のろう材に関する。   The present invention relates to a low melting point brazing material suitable for brazing of an aluminum-based metal (aluminum or aluminum alloy).

アルミニウム系金属のろう付けには、従来一般的にＡｌ−Ｓｉ系合金からなるろう材が使用されている。Ａｌ−Ｓｉ系合金のろう材はＪＩＳ Ｚ３２６３にも規定されており、線材の他、シート材も広く供給されている。それらのろう材の液相線温度は最も低いもので約５８０℃である。ろう付け温度は必然的にそれより高い温度となる。   Conventionally, a brazing material made of an Al—Si alloy is generally used for brazing an aluminum-based metal. The brazing material of the Al—Si alloy is also defined in JIS Z3263, and sheet materials are widely supplied in addition to the wire materials. The liquidus temperature of these brazing materials is the lowest and is about 580 ° C. The brazing temperature is necessarily higher than that.

ろう付け接合のなかでも、平板の表面同士を全面でタイトに接合するような「面接合」の場合には、被接合材料の間にろう材とフラックスを挟んだ状態で、材料全体を炉に装入して加熱する手法が採用されることが多い。この場合、ろう材としては線材よりもシート材の方が一般的には使いやすい。   In the case of “surface bonding” in which the surfaces of flat plates are tightly bonded together over the entire surface, the entire material is placed in a furnace with the brazing material and flux sandwiched between the materials to be bonded. The method of charging and heating is often employed. In this case, the sheet material is generally easier to use as the brazing material than the wire material.

材料全体を炉に装入する「面接合」の手法において、被接合材料の温度をできるだけ低い温度に維持したい場合には、ろう付け温度を低減することが望まれる。ろう付け温度の低減には、融点が低いろう材が必要となる。アルミニウム系金属のろう付けに適用可能な低融点の金属としてＡｌ−Ｃｕ−Ｓｉ系合金が知られている。特にＡｌ−２７％Ｃｕ−４.７％Ｓｉ組成付近の三元共晶点の周辺において液相線温度が５２０〜５４０℃程度のろう材が実現でき、線材として一部の用途で利用されることがある。   In the “surface bonding” technique in which the entire material is charged into the furnace, it is desirable to reduce the brazing temperature when it is desired to maintain the temperature of the material to be bonded as low as possible. In order to reduce the brazing temperature, a brazing material having a low melting point is required. An Al—Cu—Si based alloy is known as a low melting point metal applicable to brazing of an aluminum based metal. In particular, a brazing material having a liquidus temperature of about 520 to 540 ° C. can be realized in the vicinity of a ternary eutectic point near the Al-27% Cu-4.7% Si composition, and is used as a wire material in some applications. Sometimes.

しかし、この三元共晶点周辺のＡｌ−Ｃｕ−Ｓｉ系合金は非常に脆く、シート材に加工することは極めて困難である。このため、「面接合」に適したシート状のＡｌ−Ｃｕ−Ｓｉ系合金のろう材は提供されていないのが現状である。   However, the Al—Cu—Si based alloy around this ternary eutectic point is very brittle and it is extremely difficult to process it into a sheet material. For this reason, the present condition is that the brazing material of the sheet-like Al-Cu-Si type alloy suitable for "surface joining" is not provided.

脆い金属材料の箔体を製造する手法として急冷凝固法が知られている。特許文献１にはＡｌ−Ｃｕ−Ｓｉ系合金に単ロール法による急冷凝固法を適用して箔状のろう材を製造することが記載されている。合金組成としては、Ｃｕ：２５〜４０％、Ｓｉ：５〜１５％、残部実質的にＡｌからなるものが開示されている。しかしながら本発明者らの検討によれば、この組成範囲では、急冷凝固箔体を得ることは可能であるものの、ボビンに巻き取るに足る可撓性（フレキシビリティー）を有するものを安定して製造することは非常に難しいことがわかった。すなわち、得られた箔体は折り曲げに耐えることができない程に脆いものとなりやすく、工業製品としての量産は困難である。   A rapid solidification method is known as a technique for producing a foil body of a brittle metal material. Patent Document 1 describes that a foil-like brazing material is manufactured by applying a rapid solidification method by a single roll method to an Al—Cu—Si based alloy. As an alloy composition, Cu: 25 to 40%, Si: 5 to 15%, and the balance substantially consisting of Al are disclosed. However, according to the study by the present inventors, in this composition range, although it is possible to obtain a rapidly solidified foil body, it is possible to stably stabilize the one having flexibility enough to be wound on a bobbin. It turned out to be very difficult to manufacture. That is, the obtained foil body tends to be so brittle that it cannot withstand bending, and mass production as an industrial product is difficult.

特開平４−１６２９８１号公報Japanese Patent Laid-Open No. 4-162981

本発明は、アルミニウム系金属の「面接合」を行う場合に適した低融点のろう材であって、箔状の形状を有する可撓性に優れたものを提供することを目的とする。   An object of the present invention is to provide a brazing material having a low melting point suitable for “surface bonding” of an aluminum-based metal, and having a foil shape and excellent flexibility.

上記目的は、質量％で、Ｃｕ：１０.０〜２４.５％、Ｓｉ：４.０〜１０.０％、残部Ａｌおよび不可避的不純物からなり、ＣｕとＳｉの含有量が図１のＡ−Ｂ−Ｃ−Ｄ−Ｅ−Ｆ−Ａを結ぶ直線に囲まれる範囲（境界を含む）にある化学組成を有する急冷凝固箔体を用いた平均厚さ１５〜１００μｍの箔状ろう材によって達成される。   The purpose is mass%, Cu: 10.0 to 24.5%, Si: 4.0 to 10.0%, the balance Al and inevitable impurities, and the contents of Cu and Si are shown in FIG. Achieved by a brazing filler metal having an average thickness of 15 to 100 μm using a rapidly solidified foil body having a chemical composition in a range (including a boundary) surrounded by a straight line connecting -B-C-D-E-F-A Is done.

ここで、図１は横軸をＣｕ含有量（質量％）、縦軸をＳｉ含有量（質量％）とする直交座標系である。上記各点の座標は、Ａ（１０，１０）、Ｂ（２０，１０）、Ｃ（２４.５，８）、Ｄ（２４.５，４）、Ｅ（１６，４）、Ｆ（１０、７）である。   Here, FIG. 1 is an orthogonal coordinate system in which the horizontal axis represents Cu content (mass%) and the vertical axis represents Si content (mass%). The coordinates of each point are A (10, 10), B (20, 10), C (24.5, 8), D (24.5, 4), E (16, 4), F (10, 7).

本発明によれば、アルミニウム系金属のろう付けに使用するＡｌ−Ｃｕ−Ｓｉ系のろう材において、可撓性を有する箔状のものが提供可能となった。このろう材はボビンに巻き付けることが可能であり、取り扱い時に破断することもないので、ろう付けによる「面接合」が必要な用途に容易に適用することができる。このろう材は従来一般的なＡｌ−Ｓｉ系のろう材よりも融点が低いので、ろう付け温度を引き下げることができる。   ADVANTAGE OF THE INVENTION According to this invention, it became possible to provide the foil-shaped thing which has flexibility in the brazing material of Al-Cu-Si type used for brazing of an aluminum-type metal. Since this brazing material can be wound around a bobbin and does not break during handling, it can be easily applied to applications requiring “surface bonding” by brazing. Since this brazing material has a melting point lower than that of a conventional Al-Si brazing material, the brazing temperature can be lowered.

Ａｌ−Ｃｕ−Ｓｉ系合金におけるＣｕおよびＳｉ含有量と、得られる急冷凝固箔体の可撓性の関係を表すグラフ。The graph showing Cu and Si content in an Al-Cu-Si type alloy, and the relationship of the flexibility of the rapidly solidified foil body obtained.

発明者らは、Ａｌ−Ｃｕ−Ｓｉ系合金について、三元共晶組成の周辺域における急冷凝固箔体の製造性を詳細に調査した。その結果、三元共晶点（Ａｌ−２７％Ｃｕ−４.７％Ｓｉ組成付近）に近い組成では単ロール法により急冷凝固箔体の作製は可能であるものの、得られる箔体は非常に脆く、ボビンに巻き付けることができないほどに可撓性に乏しいものとなりやすい。ところが、三元共晶点の周辺のうち、Ａｌ含有量が多い側において、可撓性の良好な急冷凝固箔体が得られやすい領域があることがわかった。すなわち厚さ１５〜１００μｍ程度の急冷凝固箔体が製造可能な一般的な単ロール法による冷却条件において、曲げても破断せず、ボビンに巻き付けることが十分に可能な程度に可撓性が良好である箔体が容易に得られる領域があることが明らかとなった。   The inventors investigated in detail about the manufacturability of the rapidly solidified foil body in the peripheral region of the ternary eutectic composition for the Al—Cu—Si based alloy. As a result, although the composition close to the ternary eutectic point (near Al-27% Cu-4.7% Si composition) can be rapidly solidified foil body by the single roll method, the obtained foil body is very It is brittle and tends to be so inflexible that it cannot be wound around a bobbin. However, it has been found that there is a region where a rapidly solidified foil body with good flexibility can be easily obtained on the side with a large Al content in the vicinity of the ternary eutectic point. That is, it is flexible enough to be wound around a bobbin under the cooling conditions by a general single roll method capable of producing a rapidly solidified foil body having a thickness of about 15 to 100 μm, without being broken even when bent. It has become clear that there is a region where the foil body can be easily obtained.

三元共晶組成よりもＡｌ含有量が多い特定の領域で急冷凝固箔体の可撓性が良好となる理由については必ずしも明確ではないが、そのような領域では、比較的延性に富むと考えられるＡｌリッチ相（平衡状態での初晶Ａｌ相に比較的近い組成の相）の割合が多くなり、脆いと考えられるＡｌ＋Ｃｕ＋Ｓｉ相（平衡状態での三元共晶に比較的近い組成の相）の割合が少なくなることが影響しているものと推察される。発明者らの検討によると、得られる急冷凝固箔体の可撓性はＣｕ含有量が２５質量％を境に急変し、Ｃｕ含有量が２４.５質量％以下の領域において、工業的に製品化が可能な可撓性を有する急冷凝固箔体を安定して得ることが可能な組成範囲がある。   The reason why the rapidly solidified foil body has good flexibility in a specific region where the Al content is higher than the ternary eutectic composition is not necessarily clear, but in such a region, it is considered to be relatively ductile. Al-rich phase (phase of composition relatively close to primary Al phase in equilibrium) is increased, and Al + Cu + Si phase (phase of composition relatively close to ternary eutectic in equilibrium) considered to be brittle It is inferred that the decrease in the ratio of According to the inventors' investigation, the flexibility of the rapidly solidified foil body obtained is suddenly changed when the Cu content is 25% by mass, and in the region where the Cu content is 24.5% by mass or less, the product is industrially manufactured. There is a composition range in which a rapidly cooled and solidified foil body having flexibility that can be converted into a stable shape can be obtained.

具体的には、Ａｌ−Ｃｕ−Ｓｉ系合金において、ＣｕとＳｉの含有量が図１のＡ−Ｂ−Ｃ−Ｄ−Ｅ−Ｆ−Ａを結ぶ直線に囲まれる範囲（境界を含む）にある組成範囲では、良好な可撓性が得られることが確認された。   Specifically, in an Al—Cu—Si based alloy, the content of Cu and Si is within a range (including a boundary) surrounded by a straight line connecting A—B—C—D—E—F—A in FIG. It was confirmed that good flexibility can be obtained in a certain composition range.

図１の直線ＦＡよりＣｕ含有量が低い領域、Ａ−Ｂ−Ｃを直線で結ぶ境界よりＳｉ含有量が高い領域、およびＤ−Ｅ−Ｆを直線で結ぶ境界よりＳｉ含有量が低い領域では、それぞれ合金の融点が高くなり、従来のＡｌ−Ｓｉ系合金ろう材を使用する場合と比べて、ろう付け温度の大幅な引き下げは期待できない。直線ＣＤよりＣｕ含有量が高く三元共晶組成に近づく領域では、融点が低くなる反面、可撓性の良い急冷凝固箔の安定的な製造が非常に難しくなる。特に好ましい組成領域として図１のＨ（１５，１０）−Ｂ−Ｃ−Ｄ−Ｅ−Ｇ（１５，４.５）−Ｈを結ぶ直線に囲まれる範囲（境界を含む）の組成を採用することができる。あるいは、図１のＫ（１９，１０）−Ｂ−Ｃ−Ｄ−Ｅ−Ｊ（１９，４.５）−Ｋを結ぶ直線に囲まれる範囲（境界を含む）の組成に制限してもよい。なお、得られた急冷凝固箔体は、そのままの厚さでろう材製品として利用してもよいし、必要に応じて調質圧延により厚さを調整することもできる。   In the region where the Cu content is lower than the straight line FA in FIG. 1, the region where the Si content is higher than the boundary connecting the A-B-C lines, and the region where the Si content is lower than the boundary connecting the D-E-F lines The melting point of each alloy becomes high, and the brazing temperature cannot be expected to be greatly reduced as compared with the case where a conventional Al—Si alloy brazing material is used. In the region where the Cu content is higher than that of the straight CD and approaches the ternary eutectic composition, the melting point is lowered, but it is very difficult to stably produce a rapidly solidified foil having good flexibility. As a particularly preferable composition region, a composition in a range (including a boundary) surrounded by a straight line connecting H (15,10) -BCDDEG (15,4.5) -H in FIG. 1 is adopted. be able to. Or you may restrict | limit to the composition of the range (a boundary is included) enclosed by the straight line which connects K (19,10) -BCDDEJ (19,4.5) -K of FIG. . In addition, the obtained rapidly solidified foil body may be used as a brazing material product with a thickness as it is, and the thickness can be adjusted by temper rolling as necessary.

図１のＡ−Ｂ−Ｃ−Ｄ−Ｅ−Ｆ−Ａを結ぶ直線に囲まれる範囲（境界を含む）にある領域、およびそれより共晶組成に近い領域にある種々の組成のＡｌ−Ｃｕ−Ｓｉ系合金について、単ロール法による急冷凝固法により急冷凝固箔体の製造を試みた。Ｃｕ、Ｓｉの残部はＡｌである。冷却ロール（単ロール）は銅製である。スリット状の開口を有するノズルを下部に備える石英管の内部で、成分調整された原料を高周波加熱して溶融させ、その溶融金属を高速で回転する銅ロール表面にロール直近から噴射させることにより、平均厚さ２５〜６０μｍの急冷凝固箔体を得た。雰囲気は大気圧下のＡｒガス雰囲気とし、噴射用のガスもＡｒとした。ノズルのスリットは０.５ｍｍ×５〜１０ｍｍとした。得られる急冷凝固箔体はリボン状のものであり、その幅はスリットの長さ（５〜１０ｍｍ）とほぼ等しくなる。   Al-Cu having various compositions in a region (including the boundary) surrounded by a straight line connecting A-B-C-D-E-F-A in FIG. 1 and in a region closer to the eutectic composition. With respect to the Si-based alloy, an attempt was made to produce a rapidly solidified foil body by a rapid solidification method using a single roll method. The balance of Cu and Si is Al. The cooling roll (single roll) is made of copper. Inside the quartz tube provided with a nozzle having a slit-like opening in the lower part, the component-adjusted raw material is melted by high-frequency heating, and the molten metal is sprayed on the surface of the copper roll rotating at high speed, A rapidly solidified foil body having an average thickness of 25 to 60 μm was obtained. The atmosphere was an Ar gas atmosphere under atmospheric pressure, and the gas for injection was also Ar. The slit of the nozzle was 0.5 mm × 5 to 10 mm. The obtained rapidly solidified foil body is in the form of a ribbon, and the width thereof is substantially equal to the length of the slit (5 to 10 mm).

得られた急冷凝固箔体のリボンを手作業にて直径１５ｍｍのボビンにタイトに巻き付ける操作を行うことにより、可撓性を評価した。ボビンへの巻き付け作業が十分に可能であるものは、「面接合」を行うろう付けに供するうえで実用的な可撓性を有していると考えられる。そこで、以下の基準でろう材としての可撓性を評価した。
可撓性良好；箔体に割れを生じさせることなくボビンへの巻き付けが可能（○印）。
可撓性不良；脆いためにボビンへの巻き付けが困難（●印）。
その結果を図１中に示す。 Flexibility was evaluated by performing an operation of tightly winding the ribbon of the obtained rapidly solidified foil body around a bobbin having a diameter of 15 mm. Those that can be sufficiently wound around the bobbin are considered to have practical flexibility when used for brazing for “surface bonding”. Therefore, the flexibility as a brazing material was evaluated according to the following criteria.
Good flexibility: Can be wound around bobbins without causing cracks in the foil (circles).
Poor flexibility; difficult to wrap around bobbin due to brittleness (● mark).
The result is shown in FIG.

図１からわかるように、三元共晶点（Ａｌ−２７％Ｃｕ−４.７％Ｓｉ組成付近）に近い組成では、可撓性の良好な急冷凝固箔体を得ることが難しい。これに対し、本発明で規定するＡ−Ｂ−Ｃ−Ｄ−Ｅ−Ｆ−Ａを結ぶ直線に囲まれる範囲（境界を含む）では、可撓性の良好な急冷凝固箔体が安定して得られた。なお、この試験において良好な可撓性が得られた組成の合金は、工業的により幅広の急冷凝固箔体の製造が可能であると考えられる。   As can be seen from FIG. 1, it is difficult to obtain a rapidly solidified foil body with good flexibility at a composition close to the ternary eutectic point (near the Al-27% Cu-4.7% Si composition). On the other hand, in the range (including the boundary) surrounded by the straight line connecting A-B-C-D-E-F-A defined in the present invention, the rapidly solidified foil body having good flexibility is stable. Obtained. In addition, it is thought that the alloy of the composition from which favorable flexibility was obtained in this test can manufacture a rapidly solidified foil body wider than industry.

実施例１で作製したいくつかの急冷凝固箔体を用いて、示差熱分析により完全に溶融する温度（液相線温度に相当する温度）を調べた。示差熱分析の試験条件は以下のとおりである。
・雰囲気；窒素
・昇温条件；常温から６００℃まで１０℃／ｍｉｎの昇温速度で昇温
結果を表１中に示す。 Using several rapidly solidified foil bodies produced in Example 1, the temperature at which it was completely melted by differential thermal analysis (temperature corresponding to the liquidus temperature) was examined. The test conditions for differential thermal analysis are as follows.
-Atmosphere: Nitrogen-Temperature rising condition: Table 1 shows the results of temperature rising from room temperature to 600 ° C at a temperature rising rate of 10 ° C / min.

次にこれらのＡｌ−Ｃｕ−Ｓｉ系合金の箔体をろう材に用いて、アルミニウム板（ＪＩＳ Ｈ４０００に規定されるＡ１０５０）と、溶融アルミニウムめっきステンレス鋼板（ＳＵＳ４３０の表面に厚さ約２０μｍのＡｌ−９質量％Ｓｉめっき層を有するもの）の面接合を試みた。急冷凝固箔体の平均厚さが４０μｍを超えているものについては、調質圧延により厚さを４０μｍとしたのち、箔状ろう材として使用した。アルミニウム板および溶融アルミニウムめっきステンレス鋼板とも、板厚は１.０ｍｍであり、試料寸法は２０×３０×１.０ｍｍである。Ｃｓ−Ａｌ−Ｆ系化合物を主成分とするフラックスを使用し、ろう材およびフラックスを両材料の間の全面に挟んでサンドイッチ状に積み重ねた状態とし、特に荷重を付与せずそのまま所定の温度に昇温した炉内（大気雰囲気）に装入した。ろう付け温度は５５０℃および５７０℃とした。ろう付け温度での保持時間は１ｍｉｎとした。   Next, using these Al-Cu-Si alloy foils as a brazing material, an aluminum plate (A1050 defined in JIS H4000) and a hot-dip aluminum-plated stainless steel plate (SUS430 with a thickness of about 20 μm Al) (Those having a -9 mass% Si plating layer) were tried. For the rapidly solidified foil body having an average thickness exceeding 40 μm, the thickness was adjusted to 40 μm by temper rolling and then used as a foil-like brazing material. Both the aluminum plate and the hot-dip aluminized stainless steel plate have a plate thickness of 1.0 mm and a sample size of 20 × 30 × 1.0 mm. A flux mainly composed of a Cs-Al-F compound is used, and a brazing material and a flux are sandwiched between the two surfaces and stacked in a sandwich shape. The reactor was charged into the heated furnace (atmosphere). The brazing temperatures were 550 ° C and 570 ° C. The holding time at the brazing temperature was 1 min.

試料を炉から取り出した後、２枚の板が容易に分離しないものについては、試料の中心を通り長手方向および厚さ方向に平行な断面の顕微鏡観察を行い、アルミニウム板／ろう材界面、ろう材／アルミニウムめっき鋼板界面のいずれにおいても、非接合部（欠陥部分）のトータル長さが界面全長の１０％以下であったものを○（ろう付け性；良好）、それ以外のもの（２枚の板が容易に分離したものを含む）を×（ろう付け性；不良）と判定した。
結果を表１に示す。 After removing the sample from the furnace, if the two plates are not easily separated, perform a microscopic observation of the cross section passing through the center of the sample and parallel to the longitudinal direction and the thickness direction. In any of the metal / aluminum-plated steel plate interfaces, the one where the total length of the non-joined portion (defect portion) was 10% or less of the total length of the interface was ○ (brazing property: good), and the others (2 sheets) ) (Including those easily separated) were determined as x (brazing ability; poor).
The results are shown in Table 1.

表１からわかるように、本発明で規定する組成域において、完全に溶融する温度が５８０℃より低い箔体が得られる。いずれの試料も５７０℃以下のろう付け温度で健全な「面接合」が可能であり、従来のＡｌ−Ｓｉ合金系ろう材よりも低温でのろう付けが可能であることが確認された。   As can be seen from Table 1, in the composition range defined in the present invention, a foil body having a melting temperature lower than 580 ° C. is obtained. All samples were able to perform sound “surface bonding” at a brazing temperature of 570 ° C. or lower, and it was confirmed that brazing at a lower temperature than conventional Al—Si alloy brazing materials was possible.

Claims (1)

質量％で、Ｃｕ：１０.０〜２４.５％、Ｓｉ：４.０〜１０.０％、残部Ａｌおよび不可避的不純物からなり、ＣｕとＳｉの含有量が図１のＡ−Ｂ−Ｃ−Ｄ−Ｅ−Ｆ−Ａを結ぶ直線に囲まれる範囲（境界を含む）にある化学組成を有する急冷凝固箔体を用いた平均厚さ１５〜１００μｍの箔状ろう材。   1% by mass, Cu: 10.0 to 24.5%, Si: 4.0 to 10.0%, balance Al and unavoidable impurities, and the contents of Cu and Si are ABC in FIG. A foil brazing material having an average thickness of 15 to 100 μm using a rapidly solidified foil body having a chemical composition in a range (including a boundary) surrounded by a straight line connecting D-E-F-A.

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