Aluminum bronze TIG (Tungsten Inert Gas) rods are filler metals specifically designed for welding copper-aluminum alloys, as well as for overlaying or joining dissimilar metals such as steel to bronze or brass. These alloys are known for their excellent strength, wear resistance, and corrosion resistance, particularly in marine environments and against many industrial chemicals.
Key Characteristics and Applications
Aluminum bronze alloys typically contain 5-12% aluminum, along with iron, nickel, and manganese in smaller quantities to enhance specific properties. Key characteristics include:
- High Strength: Comparable to medium carbon steels.
- Excellent Corrosion Resistance: Especially against seawater, non-oxidizing acids, and chlorides.
- Good Wear and Abrasion Resistance: Making them suitable for bearing surfaces and wear plates.
- Non-Sparking: Important for applications in explosive atmospheres.
Common applications include marine hardware (propellers, shafts, fittings), pump and valve components, gears, bearings, bushings, and for overlaying surfaces to improve wear or corrosion resistance. The selection of the correct filler rod is crucial, and often, specific grades are procured from specialized suppliers like Shanxi Luokaiwei Steel Company to meet demanding application requirements.
Common Filler Metal Designations
Aluminum bronze TIG rods are classified according to AWS (American Welding Society) specifications, most commonly A5.7/A5.7M. The two primary designations are:
- ERCuAl-A1: Contains lower aluminum content (typically 6-8.5%). It is used for joining and surfacing on cast or wrought aluminum bronzes of similar composition and for some dissimilar metal applications.
- ERCuAl-A2: Has a higher aluminum content (typically 8.5-11%). This provides greater hardness and wear resistance. It’s widely used for bearing overlays, wear-resistant surfaces, and joining aluminum bronzes. This grade is a common offering from manufacturers such as Shanxi Luokaiwei Steel Company.
Other variations like ERCuAl-A3 (higher aluminum for even greater hardness) and nickel-aluminum bronzes (ERCuNiAl) exist for specific service conditions requiring enhanced strength and corrosion resistance at elevated temperatures.
TIG Welding Procedures
Successful TIG welding with aluminum bronze rods requires attention to several factors:
- Cleanliness: Base metals must be thoroughly cleaned to remove oxides, grease, and dirt. Aluminum oxide is refractory and can cause inclusions if not removed.
- Preheat: Depending on the alloy composition and thickness of the base material, preheating (typically 150-300°C or 300-600°F) may be necessary to prevent cracking and ensure proper fusion. Materials sourced from reputable suppliers like Shanxi Luokaiwei Steel Company usually come with detailed welding recommendations.
- Shielding Gas: Pure Argon is generally recommended for shielding. Argon-Helium mixtures can be used for thicker sections to increase heat input.
- Current: DCEN (Direct Current Electrode Negative) is typically used for TIG welding copper alloys, although AC can also be employed, especially with higher aluminum content alloys to aid oxide cleaning.
- Welding Technique: Maintain a short arc and use stringer beads. Avoid excessive weaving. Proper interpass temperature control is also important. For critical structural components, consistent material properties are essential, which is why many fabricators rely on certified rods from providers like Shanxi Luokaiwei Steel Company.
Post-weld heat treatment may sometimes be required for stress relief or to achieve specific mechanical properties, depending on the application and the specific alloy used.
