JPS60224734A - Aluminum alloy suitable for zincate treatment - Google Patents

Abstract

PURPOSE:To form a uniform zincate film having superior adhesion when a zincate film is formed as an underlayer on an Al alloy plate by pretreatment before plating with a heavy metal, by adding specified metallic elements to the Al alloy. CONSTITUTION:When the surface of an Al alloy is plated with a heavy metal such as Cu, Ni, Cr or Sn, to the alloy are added 0.04-0.15wt% at least two kinds of elements which reduce cathodic polarization in an alkaline bath such as Cu, Zn, Ni and Mn. The surface of the resulting Al alloy is degreased, cleaned, and etched by immersion in an aqueous NaOH soln. having 10% concn. at 70 deg.C for 30sec. The etched surface is washed neutralized with an acid, and treated with an aqueous soln. contg. ZnO and NaOH for 1min to form a uniform zincate film having superior adhesion on the etched surface. The surface of the Al alloy coated with the zincate film is electroplated with a heavy metal such as Cu, Ni, Cr or Sn according to the purpose for which the alloy is used.

Description

【発明の詳細な説明】 本光明は、ジンケート処理（亜鉛置換処理）に適したも
ので、被覆されるジンケート皮膜が均一で密着性に優れ
た表面を有するアルミニウム合金に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aluminum alloy that is suitable for zincate treatment (zinc substitution treatment) and has a surface on which a zincate film is uniform and has excellent adhesion.

一般にアルミニウム又はアルミニウム台金（以下単にア
ルミニウム合金という）のジンケート処理はアルミニウ
ム合金の板材又は型材に、銅、ニッケル、クロム、スズ
等の重金属のメッキを行うに当たり下地用前処理として
実施されたり、あるいは、アルミニウム材料か自動車な
どの熱交換器部材として利用される場合、カソード防食
用犠牲陽極層付与のため等に利用されている。In general, zincate treatment of aluminum or aluminum base metal (hereinafter simply referred to as aluminum alloy) is carried out as a pretreatment for the base when plating heavy metals such as copper, nickel, chromium, and tin on aluminum alloy plates or shapes, or When the aluminum material is used as a heat exchanger member for automobiles, it is used to provide a sacrificial anode layer for cathodic corrosion protection.

現在行われているジンケート処理法では均一で密着性の
優れたジンケート皮膜を得るため、エツチング等の前処
理条件、浴組成などのジンケート処理条件、あるいは二
重又は三重のジンケート処理を行ったりしているが、必
らずしも十分満足のゆくものではない。In the currently used zincate treatment methods, in order to obtain a uniform and highly adhesive zincate film, pretreatment conditions such as etching, zincate treatment conditions such as bath composition, or double or triple zincate treatment are performed. However, it is not always completely satisfactory.

本発明者等は、アルミニウム合金表面に均一で密着性に
優れたジンケート皮膜を得るため種々検討する段階で、
ジンケート皮膜の良好な生成のためには、アルミニウム
合金表面の酸化皮膜によるバリヤー性とカソード分極特
性が深く関連するという知見を得た。The present inventors were at the stage of conducting various studies in order to obtain a zincate film with uniformity and excellent adhesion on the surface of an aluminum alloy.
We have found that the barrier properties of the oxide film on the aluminum alloy surface and the cathode polarization characteristics are closely related to the formation of a good zincate film.

寸なわら、塩基性浴中でカソード分極を小さくするよう
な、銅、亜鉛、ニッケル、マンガン等の元素を２種以上
含有し、その含有量が０．０４〜０．１５重量％（以下
％はすへて重・宣％を示す。）残りが不可避不純物とア
ルミニウムよりなるアルミニウム合金を、苛性ソーダで
エツチングした後中和するか、付着油分を有機溶剤等で
除去した後でジンケート処理することにより、アルミニ
ウム合金表面に、均一で極めて密着性の優れたジンケー
ト皮膜を得て本発明を完成した。However, it contains two or more elements such as copper, zinc, nickel, and manganese that reduce cathode polarization in a basic bath, and the content is 0.04 to 0.15% by weight (hereinafter referred to as %). ) The aluminum alloy, the remainder of which consists of unavoidable impurities and aluminum, is etched with caustic soda and then neutralized, or adhering oil is removed with an organic solvent and then treated with zincate. The present invention was completed by obtaining a uniform and highly adhesive zincate film on the surface of an aluminum alloy.

以下本発明のアルミニウム合金成分につき、その成分範
囲限定理由を説明する。The reasons for limiting the range of the aluminum alloy components of the present invention will be explained below.

１　）Ｆｅ　＋Ｓｉ成分 Ｆｅ　＋３ｉ成分の成分範囲は実用上０．２８〜１．０
０％が好ましい。すなわち、Ｆｅ　＋３ｉ成分が０．２
８％より低い場合には、地金コストの面で有利でなく、
また、１．００％より高い場合は、変形抵抗が大となり
、ピックアップ、ダイマーク等の表面欠陥が起き易く適
当でない。1) Fe + Si component The composition range of Fe + 3i component is practically 0.28 to 1.0
0% is preferred. That is, the Fe +3i component is 0.2
If it is lower than 8%, it is not advantageous in terms of bullion cost,
On the other hand, if it is higher than 1.00%, the deformation resistance becomes large and surface defects such as pickups and die marks are likely to occur, which is not suitable.

２）鋼、亜鉛、ニッケル、マンガン等の含有酸分銅、亜
鉛、ニッケル、マンガンの群より選ばれた２種以上の成
分の含有量が０．０４％より少い場合には、均一で極め
て密着性に優れたジンケート皮膜が術ずらく、０．１５
％を越えると変形抵抗が大となるためその含有成分範囲
を０．０４〜０．１５％と定めた。また、含有成分を２
種以上としたのは、単独含有成分ではジンケート皮膜の
望ましい均一性と密着性が得られないからである。2) If the content of two or more components selected from the group of steel, zinc, nickel, manganese, etc. is less than 0.04%, it will be uniform and extremely adhesive. Zincate film with excellent properties is difficult to operate, 0.15
Since the deformation resistance becomes large when the content exceeds 0.04% to 0.15%. In addition, the ingredients contained in 2
The reason why the amount is more than 50% is because the desired uniformity and adhesion of the zincate film cannot be obtained with a single component.

尚、本発明アルミニウム合金は、不可避不純物として、
Ｍａ　、Ｔｉ　、Ｇａ等の各種成分をそれぞれ０．０１
％以下含有してもよい。In addition, the aluminum alloy of the present invention contains as inevitable impurities:
Various components such as Ma, Ti, Ga, etc. are each 0.01
% or less may be contained.

実施例１ 各種アルミニウム地金を溶製して巾：１５０５ｍ。Example 1 Width: 1505m made by melting various aluminum ingots.

長さ：２００１１１１１．厚さ；３Ｑｍｍのスラブを第
１表に示す成分範囲でそれぞれ製造した。これらの各ス
ラブを５８０℃で８時間均熱化処理後、５００℃で熱間
圧延し、中間焼鈍を施しながら０．２１１Ｉｌ迄冷間圧
延した。このようにして得た冷間圧延板を５０Ｘ１５０
ｍｓ＋に切断した。ついで、これら試験片につき、下記
条件でそれぞれジングー１〜皮膜処理及びニッケルメッ
キ処理した。すなわち、トリクロールエチレン蒸気中で
約５分間の溶剤脱脂を行い、ついで、７０℃の１０％苛
性ソーダ溶液に３０秒間浸漬し水洗後に、空温に保った
１０％硝酸溶液にて３０秒間中和処理した。このように
処理した試験片を水洗後、７０ｏの鹸化亜鉛と３５０ｇ
の苛性ソーダを１えの純水に溶解し、２５℃に保った水
溶液中で１分間処理して各試験片上にジンケート皮膜を
作った。さらにこれらの試験片を水洗後、２５０ｇの＠
酸ニッケル（ＮｉＳＯ４，６Ｈ２０）、５５ａの塩化ニ
ッケル（Ｎｔ　Ｃえ２，６＋−１２０）及び３Ｂ１）の
ホウ酸（８３８０３）をｉｇｌの純水に溶解して５５℃
に保った水溶液中で、電流密度３Ａ／ｄｌ１２でニッケ
ルメッキを行った。Length: 20011111. Slabs each having a thickness of 3 Qmm were manufactured using the component ranges shown in Table 1. Each of these slabs was soaked at 580° C. for 8 hours, hot rolled at 500° C., and cold rolled to 0.211 Il while being subjected to intermediate annealing. The cold-rolled plate thus obtained was 50×150
Cut at ms+. These test pieces were then subjected to Jingu 1 film treatment and nickel plating treatment under the following conditions. That is, solvent degreasing was performed for about 5 minutes in trichlorethylene vapor, then immersed in a 10% caustic soda solution at 70°C for 30 seconds, washed with water, and then neutralized for 30 seconds in a 10% nitric acid solution kept at air temperature. did. After washing the test piece treated in this way with water, 350g of saponified zinc at 70o was added.
of caustic soda was dissolved in 1 ml of pure water and treated in an aqueous solution kept at 25° C. for 1 minute to form a zincate film on each test piece. Furthermore, after washing these test pieces with water, 250 g of @
Nickel acid (NiSO4,6H20), 55a nickel chloride (NtC2,6+-120) and 3B1) boric acid (83803) were dissolved in pure water of IGL and heated at 55℃.
Nickel plating was performed in an aqueous solution maintained at a current density of 3 A/dl12.

第１表に示す如く、本発明アルミニウム合金上へのジン
グー１〜皮膜は、均一で穫めて密着性の優れたものであ
り、その後のニッケルメッキ皮膜の密着性も優れたもの
であった。As shown in Table 1, the Zingu 1 coating on the aluminum alloy of the present invention was uniform and had excellent adhesion, and the adhesion of the subsequent nickel plating film was also excellent.

実施例２ 各種アルミニウム地金を溶製して、第２表に示すような
成分範囲の直径、：１７８ＩＩ１ｍ、長奎：５００ＩＩ
ＩＩｌのビレットをそれぞれ製造した。これらのビレッ
１〜を４５０℃で加熱した後、押出法により第２図の如
きカークーラーコンデンサ用９穴偏平管を製造した。Example 2 Various aluminum ingots were melted and the diameter of the component range as shown in Table 2: 178 II 1 m, length: 500 II
A billet of IIl was produced respectively. After heating these billets 1 to 450 DEG C., a 9-hole flat tube for a car cooler condenser as shown in FIG. 2 was manufactured by extrusion.

これらの材料を２００ｎｕｎの長さに切断後、トリクロ
ールエチレン蒸気中で５分間処理して脱脂した。ついで
、純水１え中に酸化亜鉛８０ｇと苛性ソーダ５００ｇを
溶解して５０℃に保持したジンウー１へ処理液中で５分
間処理した。本発明のアルミニウム合金試験片＜ＮＯ’
１６〜１８）はいずれも第２表中に示した如く、均一で
極めて密着性の優れたジンケート皮膜で被覆されていた
。尚ジンケート皮膜、メッキ皮膜等の密着性の評価は、
セロテープ剥離で行い、皮膜の均一性については、光学
顕微鏡下で目視にて行った。表中試験結果は、Ｏ・・・
良好な表面 △・・・や）不十分な表面 Ｘ・・・フクレ等の欠陥の生じた表ｉｉｉで表示した。After cutting these materials into lengths of 200 nm, they were degreased by treatment in trichlorethylene vapor for 5 minutes. Next, 80 g of zinc oxide and 500 g of caustic soda were dissolved in pure water 1, and Jinwoo 1, which was maintained at 50° C., was treated in the treatment solution for 5 minutes. Aluminum alloy test piece of the present invention <NO'
Nos. 16 to 18) were all coated with a uniform and highly adhesive zincate film as shown in Table 2. In addition, evaluation of adhesion of zincate film, plating film, etc.
This was done by peeling off with cellophane tape, and the uniformity of the film was checked visually under an optical microscope. The test results in the table are O...
Good surface Δ...or poor surface X...defects such as blisters were shown in Table iii.

また、ジンケート皮躾量の測定は、３０％硝酸中で１分
間浸漬後被覆皮膜を溶解除去して重量法で梓出した。さ
らにジンケート処理後、６００℃で１０分間加熱処理し
たアルミニウム合金に対して、５００時間のＣＡＳＳＫ
験を行い耐孔食性を調ｌ＼だ。孔食がＺｎ拡散層内（１
００μ）で止つ−（いるものをＯ，Ｚｎ拡散層を越えて
す）んでいるものを犠牲陽極効果不十分としてＸで表わ
した。Further, the amount of zincate peeling was measured by immersing the sample in 30% nitric acid for 1 minute, dissolving and removing the coating film, and weighing the sample using a gravimetric method. Furthermore, after zincate treatment, aluminum alloy was heat treated at 600℃ for 10 minutes, and 500 hours of CASSK
Tests were conducted to determine pitting corrosion resistance. Pitting corrosion occurs in the Zn diffusion layer (1
If the sacrificial anode effect is insufficient, it is indicated by X if the sacrificial anode effect is insufficient.

第１表及び第２表より明らかな如く、本発明合金はジン
グー１〜処理を行った場合、被覆皮膜量の多少に関係な
く、ジンフート皮膜は、均一で極めて密着性に優れたも
のとなり、Ｎｉメッキ等のメッキ処理やフラックスろう
付は等の拡散熱処理を行った後でも前記皮膜を維持でき
るので各種のメッキ用下地としたり、熱交換器部材に耐
孔食性を付与する場合等に有効に利用できるものである
。As is clear from Tables 1 and 2, when the alloy of the present invention is subjected to the Jinfu 1 treatment, the Jinfuto film becomes uniform and has excellent adhesion, regardless of the amount of coating film, and the Ni The film can be maintained even after diffusion heat treatment such as plating or flux brazing, so it can be effectively used as a base for various types of plating or when imparting pitting corrosion resistance to heat exchanger components. It is possible.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明実施例のカークーラーコンデンサ用９穴
偏平管の斜視図である。FIG. 1 is a perspective view of a 9-hole flat tube for a car cooler condenser according to an embodiment of the present invention.

Claims (1)

【特許請求の範囲】 １）塩基性浴中にＪ５いて、カソード分極を小さくする
元素を、少くとも２種以上含有し、その含有ｆｉｌが０
．０４〜０．１５ｆＪｍ％Ｔ−あり、残りが不可避不純
物とアルミニウムより構成したことを特徴とするジンケ
ート処理に適したアルミニウム合金。 ２、特許請求の範囲第一項記載のアルミニウム合金にお
いて、塩基性浴中において、カソード分極を小さくする
元素が銅、亜鉛、ニッケル、マンガンの群より選ばれる
ものであり、各元素の成分範囲がそれぞれ０．０２〜０
．１３重量％であるもの。[Scope of Claims] 1) J5 is in a basic bath and contains at least two or more elements that reduce cathode polarization, and the content fil is 0.
．． An aluminum alloy suitable for zincate treatment, characterized by having 04 to 0.15 fJm% T-, with the remainder consisting of unavoidable impurities and aluminum. 2. In the aluminum alloy according to claim 1, the element that reduces cathodic polarization in a basic bath is selected from the group of copper, zinc, nickel, and manganese, and the component range of each element is 0.02~0 respectively
．． 13% by weight.