William
11-19-2012, 09:49 AM
Interesting article on how the color around the weld can give you an idea of weld quality. May be old hat to some of the builders but I learned something new today.:cool:
Titanium 101
Pretty colors are fine for titanium jewelry. However, blue, violet, green, grey and white colors indicate atmospheric contamination in a GTA welded titanium component. In critical applications, welds exhibiting such colors may suffer reduced strength and loss of ductility and could (or must) be rejected....
Titanium and its alloys offer excellent corrosion resistance to acids, chlorides and salt; a wide continuous service temperature range, from liquid nitrogen (-322°F) to 1100°F; and the highest strength-to-weight ratio of any metal.
For example, the most widely used grade of titanium alloy, ASTM Grade 5 (Ti-6Al-4V), has a yield strength of 120,000 psi and a density of 282 lb/ft3. In comparison, ASTM A36 steel has a yield strength of 36,000 psi and a density of 487 lb/ft3, while 6061-T6 aluminum has a yield strength of 39,900 psi and density of 169 lb/ft3.
...In short, titanium is about 45 percent lighter than steel, 60 percent heavier than aluminum and more than three times stronger than either of them. While expensive initially, titanium lowers life cycle costs because of its long service life and reduced (or non-existent) maintenance and repair costs.
http://www.millerwelds.com/resources/articles/TIG-gtaw-titanium-welding
William
Titanium 101
Pretty colors are fine for titanium jewelry. However, blue, violet, green, grey and white colors indicate atmospheric contamination in a GTA welded titanium component. In critical applications, welds exhibiting such colors may suffer reduced strength and loss of ductility and could (or must) be rejected....
Titanium and its alloys offer excellent corrosion resistance to acids, chlorides and salt; a wide continuous service temperature range, from liquid nitrogen (-322°F) to 1100°F; and the highest strength-to-weight ratio of any metal.
For example, the most widely used grade of titanium alloy, ASTM Grade 5 (Ti-6Al-4V), has a yield strength of 120,000 psi and a density of 282 lb/ft3. In comparison, ASTM A36 steel has a yield strength of 36,000 psi and a density of 487 lb/ft3, while 6061-T6 aluminum has a yield strength of 39,900 psi and density of 169 lb/ft3.
...In short, titanium is about 45 percent lighter than steel, 60 percent heavier than aluminum and more than three times stronger than either of them. While expensive initially, titanium lowers life cycle costs because of its long service life and reduced (or non-existent) maintenance and repair costs.
http://www.millerwelds.com/resources/articles/TIG-gtaw-titanium-welding
William