Zinc and Tin Alloy Wire Used in Thermal Spraying for Electronic Applications

B943: Standard Specification for Zinc and Tin Alloy Wire Used in Thermal Spraying for Electronic Applications

For engineers and designers working with advanced electronic components, ensuring the reliability and longevity of critical coatings is paramount. ASTM B943 provides an essential framework for specifying zinc and tin alloy wires used in thermal spraying, a process vital for creating protective and functional layers in the electronics industry. This authoritative standard ensures that the materials used meet stringent performance requirements for these demanding applications.

What is B943?

ASTM B943, "Standard Specification for Zinc and Tin Alloy Wire Used in Thermal Spraying for Electronic Applications," is a comprehensive document developed by ASTM International. It establishes the quality and performance criteria for specific zinc and tin alloy wires intended for thermal spray processes within the electronics sector. Its primary purpose is to provide a standardized method for purchasing and manufacturing these specialized wires to ensure consistent and reliable coating outcomes.

Scope & Purpose

This standard governs the composition, dimensions, and quality of zinc and tin alloy wires designed for thermal spraying applications in the electronics industry. It specifically covers alloys such as zinc-aluminum, zinc-aluminum-copper, zinc-tin, zinc-tin-copper, and tin-zinc, with a nominal liquidus temperature not exceeding 850°F (455°C). While some of these alloys may also be used as solders or for general corrosion protection of steel, B943 focuses exclusively on their suitability for thermal spray applications within electronics, distinguishing its scope from standards for solder metal or general metallizing.

Who Must Comply?

• • Primary Audience: Materials engineers, metallurgists, quality control inspectors, manufacturing engineers, and purchasing agents involved in the procurement and utilization of thermal spray materials for electronic devices.
• • Industries Affected: Electronics manufacturing, aerospace (for specialized electronic components), and automotive (for advanced electronics requiring robust coatings).
• • Compliance Nature: Voluntary, but highly recommended for ensuring product quality, performance, and interoperability within the supply chain.
• • Enforcement: Typically enforced through contractual agreements between suppliers and purchasers, and by internal quality assurance protocols within manufacturing facilities.

Key Requirements Overview

The standard requires manufacturers to adhere to precise chemical compositions for specified zinc and tin alloys, ensuring predictable melting points and coating characteristics. Professionals must ensure that the wire supplied is clean, free from defects like corrosion, scale, or foreign material, and possesses a finish suitable for thermal spray equipment. Key provisions include strict tolerances on wire dimensions and unit weight to guarantee consistent feeding and deposition rates. Furthermore, the standard mandates that the wire be supplied in continuous lengths, with provisions for permissible splices that do not impede the spraying process.

Related Standards & References

ASTM B943 works in conjunction with other proven ASTM standards. Specification B32, "Specification for Solder Metal," is relevant for understanding the broader context of tin-based alloys, though B943 focuses on thermal spray applications. Specification B833, "Specification for Zinc and Zinc Alloy Wire for Thermal Spraying (Metallizing) for the Corrosion Protection of Steel," offers complementary guidance for zinc alloys used in different protective coating scenarios. Terminology B899, "Terminology Relating to Non-ferrous Metals and Alloys," provides essential definitions for consistent understanding of material properties.