There are a lot of uses for helium ranging from party balloons to magnetic resonance imaging machines to specialized testing equipment and, of course, helium is used as a shielding gas for welding.

Although it is the second most plentiful element in the universe, there is irony in the fact that helium is a rare element on earth and, today, there is a shortage of the gas. Since this gas cannot be replenished, the question is to what can be done to replace helium in industrial applications.

Welding, in particular, is affected by the shortage of this gas. Helium is inert and, in general, it provides excellent weld metal properties.

In gas metal arc welding – MIG welding – gas mixtures enhanced by helium provide arc stability at greater wire feed speeds, and increases weld metal deposition rates when compared to conventional argon/CO2 mixtures.

Due to helium’s greater heat conductivity, performance over mild base metal contamination also is improved, and this often helps to eliminate costly rework.

Argon/helium enhanced mixtures commonly are applied in MIG welding thick aluminum sections, greater than 12mm. The enhanced mixtures typically increase deposition rates while eliminating the need to perform preheating operations. Additionally, the use of helium enhanced shielding gas mixtures provide an improvement in the penetration profile of the completed weld deposit compared to pure argon or argon/ CO2 blends.

Praxair Inc. (www.praxair.com) identifies helium as the preferred shielding gas for laser welding. Praxair says on its Internet site that a pure helium gas shield suppresses the formation of the plasma plume in laser welding and helps to increase laser travel speed while lowering power consumption because of its greater ionization potential compared to argon.

High purity helium is a critical gas component used in the manufacturing of the resonator gas mixtures that are commonly used in CO2 lasers. High purity helium enhances gas mixtures that are introduced directly into CO2 laser resonator chambers.

Praxair’s technology mixes helium with other high purity gas components that contain carefully controlled levels of moisture and hydrocarbons, and contribute to increased beam quality, greater cutting or welding speed, and lower power levels. The mixtures also offer greater laser up-time. Praxair sells its high purity 5.5 LaserStar helium enhanced gas mixtures to maximize the performance of CO2 lasers.

To respond to both of these supplydemand issues, manufacturers of specialty gases for welding are looking at new blends that either use much less helium or no helium at all.

Praxair for example, makes a helium free mixture, Stargon, that the company said provides good corrosion resistance for a variety of welding applications including stainless steel and carbon steel.

BOC, (www.boc.com) the world’s largest helium supplier that provides nearly 30 percent of the commercially available supply, has imposed quotas on its customers because of the supply-demand imbalance, Kristina Schurr, spokeswoman for BOC, said.

The medical and health industries compete with welding for helium which is needed for equipment such as magnetic resonance imaging (MRI) machines. Because of the critical health issues related to magnetic resonance imaging, there is less rationing for medical applications than for industrial uses.

Gas producers and distributors are reluctant to talk about the helium shortage.