While titanium is 45% lighter than steel and 60% heavier than aluminum, welding this tough material can be a challenge. In fact, many of titanium’s disadvantages are the cause of its poor reputation in the welding business. At steady temperatures, welding may contaminate the material with nitrides, carbides, and oxides that may lead to low resistance, brittle results, and notch toughness. However, in high heat, titanium can become highly reactive to chemicals in its local environment.
Chlorine from cleaning compounds or human sweat can create corrosion during the welding process. Thus, the welder must be protected from local contamination as friction from grinding wheels can develop ample heat and invite the contaminants to reach the weld.
Sanitize when handling the materials
The most important step is to choose quality titanium for proper material preparation and maintenance. You will need to store all materials in a dry, clean area and ensure they are sealed and wrapped when not in use. In fact, all welders must also use clean gloves when handling materials as even clean bare hands can taint the material. Contamination from lubricants, cutting fluid, dirt, paint, and other substances may lead to embrittlement – the leading cause of weld failure.
Preparing the surface
When using quality materials such as Grade 5 Titanium, welders must understand the use of various combinations of mechanical properties, ease of fabrication, formability, corrosion resistance, and weldability. In return, welders must understand how to prepare the ideal foundation and prevent the three major mistakes when welding titanium, including:
- Using the wrong filler metal
- Insufficient quality to shielding the weld puddle
- Improper cleaning of metal
A proper method of gas distribution
Gas tungsten torches can be cooled via water or aid, depending on the preferred equipment. For welding titanium, 2% ceriated tungsten is enough to carry the required current. To provide enough coverage, most facilities use their own purse blocks from stainless steel and porous copper sheets. In return, the spongy copper works as a gas lens to distribute gas evenly.
When preparing the welding surface, use a stainless steel brush that is specifically used for titanium materials. This will cut the risks of cross-contamination against other metals. Another factor to consider is to refrain from using any chlorine-based solvent. Instead, use a carbide file to remove any marks caused by mechanical filing or grinding.