Web Menu

Product Search

Language

Share

Welding Wire for High-Strength 7XXX Alloys

-- Steady & Reliable Manufacturer --

Product Description

Specialized aluminum filler metals required to join high-strength, heat-treatable 7XXX series base metals (Aluminum-Zinc-Magnesium, e.g., 7075, 7050). The challenge is that 7XXX alloys are highly susceptible to hot cracking during welding due to their large solidification range. Fillers are typically chosen from the 5XXX series (ER5183) or a proprietary Al-Mg-Zr blend. The goal is to maximize the dilution tolerance, minimize the crack-sensitive zone, and provide a weld deposit that maintains acceptable strength and toughness, particularly in the fusion zone, where the base metal's strength is significantly reduced by the heat.

DB Certification CE Certification ABS Certification DNV Certification CCS Certification

Related Products

20+ Years Experience

Over two decades of aluminum alloy wire production expertise

International Certifications

DB, CE, ABS, DNV, CCS and other authoritative certifications

200MT Monthly Capacity

Large-scale production with consistent quality

Global Export

Exporting to over 30 countries worldwide

Introduction

The 7XXX alloys offer the highest strengths of all commercially available aluminum alloys, making them vital for high-stress applications in aerospace and sporting goods. However, they are notoriously difficult to fusion weld due to severe hot cracking. ER5356 is often considered the safest compromise, offering a wide solidification range to bridge the base metal's crack-sensitive zone. We specialize in supplying high-quality, crack-resistant fillers and technical guidance necessary to overcome the unique metallurgical challenges of welding 7XXX alloys, often recommending TIG pulse or other low-heat input techniques alongside our consumables to minimize the heat-affected zone (HAZ) weakening.

Specification

Base Metal Focus7XXX Series (Al-Zn-Mg, e.g., 7075, 7050)
Filler AlloyER5356 (Most Common), ER5183 (Higher Strength), Specialized Al-Mg-Zr
Primary ChallengeSevere Hot Cracking Susceptibility
Secondary ChallengeStrength Loss in the Heat-Affected Zone (HAZ)
Required TechniqueLow Heat Input, High Preheating (e.g., 100∘C), TIG Pulse, or FSW (preferred alternative)

Applications and Solutions

  • Aerospace and Military Structures: Joining high-performance airframe components, often in non-load-bearing or lightly loaded joints, where welding is necessary.

  • Bicycle Frames and Sporting Goods: Welding high-strength 7005 or 7050 alloys in performance-critical frames and gear.

  • Cryogenic Tanks: Welding 7XXX alloys used in low-temperature service where joint integrity and toughness are required (e.g., specific liquid oxygen tanks).

  • Repair of Extrusions: Repairing defects or adding fittings to large 7XXX extrusions commonly found in heavy machinery.

FAQ

  • Q: Why are 7XXX alloys so crack-sensitive?A: They contain high levels of Zn and Mg which form low-melting point eutectics that segregate to the grain boundaries. This forms a liquid film that persists at the end of solidification, making the weld highly susceptible to hot tearing under stress.
  • Q: Which filler is best for 7075?A: For general fusion welding, ER5356 is the most common and safest choice due to its crack resistance. However, fusion welding of 7075 in critical applications is strongly discouraged in favor of mechanical joining or Friction Stir Welding (FSW).
  • Q: Does the weld zone retain the strength of the base metal?A: No. The heat from welding completely destroys the T6 temper of the base metal in the HAZ. The joint strength can be reduced by 50% to 70%. Some strength can be recovered with post-weld solution heat treatment, but this is complex and often impractical.

Advantages and Core Features

  • Hot Cracking Mitigation: Fillers like ER5356, with their wide solidification range, significantly reduce the chance of the weld failing due to cracking as it solidifies.

  • Good Ductility: Provides a ductile weld deposit that can tolerate the significant residual stresses and thermal strains inherent in welding 7XXX alloys.

  • Acceptable Strength Compromise: Although the full base metal strength is not recovered, the filler provides the best attainable strength and toughness for fusion-welded 7XXX joints.

  • Low Weld Zone Porosity: High-quality 5XXX fillers are less prone to porosity than certain other alloys, aiding weld inspection acceptance.

Material Selection Guide

For welding 7XXX alloys, the selection is driven by crack mitigation: ER5356 is the standard. For non-load-bearing cosmetic or repair welds on 7XXX, ER4043 might be considered, but only with extreme caution and preheating. Critical structural joints should be joined by FSW or mechanical methods unless a specific, qualified Al-Mg-Zr filler is specified by the design engineer.

About Us

Coming From China, Marketing To The World.

Hangzhou Kunli welding materials Co., Ltd. is China Welding Wire for High-Strength 7XXX Alloys Manufacturers and Wholesale Welding Wire for High-Strength 7XXX Alloys OEM/ODM Suppliers. We are located in the industrial zone of Puyang Town, Xiaoshan District, Hangzhou, Zhejiang Province. It is a high-technology enterprise specializing in the research, development and manufacturing of high-performance. The company has more than 20 years of aluminum alloy wire production experience, with international advanced manufacturing equipment, complete testing equipment,stable production process and strict quality control system.
GET IN TOUCH

Send Us a Message?

Related Products

Discover our complete range of welding materials

⚡ Aluminum Wire for High Strength 7XXX Alloys ⚡ High Strength Aluminum Welding Wire ⚡ Aluminum Wire for High-Purity 5XXX Alloys ⚡ Aluminum Wire for High Heat Input Welding ⚡ High Deposition Aluminum Welding Wire ⚡ Aluminum Wire for Railway/High-Speed Rail ⚡ Aluminum Welding Wire for Automotive Components ⚡ Aluminum Welding Wire for Cryogenic Tanks ⚡ Aluminum Welding Wire for Brazing Applications ⚡ Aluminum Wire for High Purity Applications