What Are The Advantages Of 4047 Filler Alloy?

What Are The Advantages Of 4047 Filler Alloy?

Benefits Of Using 4047 Filler Alloy

In the present article, you will find information on filler alloy (4047) and its advantages. It also helps you understand if filler alloy (4047) can be substituted with filler alloy 4043.

What Are Filler Metals?

Filler metals are alloys or unalloyed metals used in welding. When heated, filler metals melt and fill in space between two close-fitting parts to form a welding joint.

Filler alloy 4047 was originally developed as a brazing alloy (BAlSi-4) or (718) taking advantage of its low melting point and narrow freezing range (1070 to 1080 °F). The main difference between 4043 and 4047 is the silicon content of these alloys. The 4043 filler alloys contain 4.5 to 6.0% silicon and the 4047 contain 11.0 to 13.0% silicon.

What Are The Advantages Of 4047 Filler Alloy?

Improved Fluidity

The higher silicon additions in the 4047 alloy result in improved fluidity (wetting action) during the welding operation. This characteristic has proven itself to be extremely desirable when welding thinner materials that are required to have leak-tight joints.

Higher Productivity

Welding procedures used in the heat exchanger fabrication industry have been improved by changing from 4043 to 4047 filler alloy. The 4047 provides exceptional fluidity, which helps to reduce weld leakage rates during the manufacturing process, thereby substantially improving productivity. Better weld quality - Additional benefits from the 4047 filler alloy over the 4043 are minimizing solidification cracking and slightly higher fillet weld shear strength.

Enhanced Cosmetic Appearance

Moving from 4043 to 4047 provides an improved cosmetic appearance, particularly when welding thin material. The improved fluidity from the additional silicon within the 4047 filler alloy can produce cosmetically pleasing and exceptionally smooth welds.

What Does the AWS (American Welding Society) Code Recommend?

In terms of the AWS D1.2 Structural Welding Code for Aluminum, 4047 is acceptable as a replacement for 4043 as both of these filler alloys have the same “F” number (F23). The 4047 filler alloy like the 4043 is suitable for elevated temperature service.

However, the same problem with 4047 as 4043 can occur if post weld anodizing is to be performed. Because of their silicon content, both of these alloys will typically turn dark gray after anodizing, and for this reason, they are usually not recommended for products requiring this type of post weld surface treatment.