These guidelines draw the user’s attention to:
ある) 錫鉛合金の特性が不明な場合, it may lead to the incorrect use of this coating;

b) Properties and preparation of the substrate;

c) Electroplating practice.

Performance of D1 coating

ISO 2179-1986 電気めっきに関する共通国家規格および仕様のガイドライン

May lead to incorrect use of this coating;

Tin-lead coating is a soft and easy to wear coating, composed of 62sn/38Pb low-eutectic alloy coating melting point as low as 183℃. This relatively low melting temperature of tin – lead alloy can be conducive to automatic welding. Under certain outdoor exposure conditions, especially under high humidity conditions, some corrosion of the tin-lead coating may occur. The thickness specified in Table 1 is the minimum value, and the thickness may be required to be greater than the specified value in Table 1 実際に使用中. Under normal indoor exposure, フェノール化合物や揮発性有機酸などの有機蒸気がない場合, コーティングは不連続で多孔質ではありません, 錫と鉛のコーティングはほとんどの金属を保護できます. コーティングの気孔率はその厚さだけで影響を受けるわけではありません, 基板材料の表面状態や実際の電気めっきプロセス条件によっても異なります。. 気孔率テストを指定するときは、これらの要素を考慮する必要があります。 (見る 10.5). 純錫メッキとの比較, この規格で指定された組成範囲内の錫鉛合金コーティングは、氷点下での製品の成長現象やアロスタティック変化をより効果的に防止できます。.

この国家規格に準拠した電気めっき層は、一般的な溶融めっき皮膜よりも薄いまたは厚い.

ISO 2179-1986 電気めっきに関する共通国家規格および仕様のガイドライン

D2 マトリックス材料の特性と準備

D2.1 Surface condition

The surface condition of the coating depends in part on the surface condition of the substrate material.

D2.2 Formation of intermetallic compounds

Due to the diffusion process between solid and solid, the coating and copper or copper based alloy will diffuse with each other, the degree of diffusion depends on time and temperature conditions, this diffusion can lead to thin coating black and welding performance deterioration. This deterioration rate varies depending on the release conditions. In poor conditions, the storage period may only be a few months.

D2.3 Diffusion of zinc

Zinc in Zinc-containing alloys such as copper diffuses to the surface through the tin-lead coating, reducing the welding properties, bond strength, and appearance of the coating (see Chapter 9).

ISO 2179-1986 電気めっきに関する共通国家規格および仕様のガイドライン

D2.4 “Difficult to clean” substrate material

Some matrix materials, such as phosphorous bronze, bronze plating and nickel-iron alloys, are difficult to perform a good chemical pre-cleaning due to the natural oxide film on their surface. If soldering properties are required for tin-lead alloy coatings, preplating nickel or copper substrates with a minimum local thickness of 25µm will be beneficial to improve soldering properties.

D2.5 Aluminum, Magnesium and Zinc Alloys These alloys are susceptible to damage by dilute acids and/or alkalis and therefore require a special pretreatment prior to electroplating the tin-lead alloy by deposition of a fairly thick (10 to 25µm) 銅, copper-tin alloy or nickel substrate.

D3 Electroplating practice

D3.1 Label wash after plating

If the coating is required for welding performance, it should be washed with an appropriate solution, のような 3%(mass ratio) lime acid or tartaric acid solution in the water washing process to ensure the removal of hydrated tin salt. If there is hydrated tin salt on the surface of the coating, it will have a harmful effect on the welding performance of the surface after drying and solidification.

ISO 2179-1986 電気めっきに関する共通国家規格および仕様のガイドライン

D3.2 Coating thickness requirements

Unless otherwise specified in GB/T12334, it should be noted that the thickness of the deposition layer specified in this standard is the minimum local thickness and not the average thickness. The AVERAGE THICKNESS TO BE ACHIEVED for a GIVEN MINIMUM LOCAL THICKNESS requirement ON THE MAIN SURFACE WILL DEPEND ON THE GEOMETRY OF BOTH the PLATE and the BATH, AND THE PLACEMENT OF THE CATHODE AND ANODE closely RELATED to BOTH. In the roll plating, especially in the roll plating of small parts, the deviation of the coating thickness conforms to the normal (Gaussian) distribution law.

During hot melt treatment, because the formation of meniscus will affect the thickness of the coating, the coating should only be evaluated for its welding performance requirements.

D3.3 Co-deposition of organic matter

Organic additives are often used in tin – lead electroplating solutions. If the coating is used for welding performance requirements, attention should be paid to the selection of organic additives to minimize co-deposition of organic matter, because organic matter may cause coating skin or blistering during melting or welding. しかし, if it is a coating on a connector, コーティングの機械的特性は、含まれる有機物の共堆積によって改善されます。.

ISO 2179-1986 電気めっきに関する共通国家規格および仕様のガイドライン

D4 ホットメルト処理

錫と鉛のコーティングは、高温の油に浸すと簡単に溶けてしまいます。, または赤外線または圧縮熱蒸気にさらされる. ホットメルトの利点は、基材の欠陥によって引き起こされる溶接性能の低下が、コーティングのホットメルトで穴のない濡れた領域として現れることができることです。. 膜厚20μm以下で効果を満足できます。. しかし, ホットメルトプロセス中に溶融したコーティングがワークピースの端に流れる可能性がある場合, の形成を避けるために、コーティングの厚さは 8μm 未満に制限する必要があります。 “ピーク” ワークの端に. ホットメルト処理は非常に明るい電気めっきには推奨されません.