CHEMETAL USA specializes in designing and machining accurate and efficient tungsten and molybdenum parts for various applications and industries. All tungsten and molybdenum materials are difficult to machine due to their high hardness, DBTT and the lack of room temperature ductility. In order to reduce the strength and increase the ductility, the work piece usually needs to be heated to above its brittle to ductile transition temperature during the machining operation. Take sintered tungsten materials as an example. The desirable machining temperature for sintered tungsten is 340~370°C in order to eliminate the brittleness. When machining sintered tungsten, the machining speed has to be high enough continuously generate a chip with a dark red color. Furthermore, the sintered tungsten requires a comparatively lower feed rate and cut depth because of the extremely high radial force. The most accomplished cutter is grade C-2 or C-3 carbide insert.
Another problem in the machining tungsten and molybdenum materials results from the surface contamination, such as the rough and stiff oxidant layer, which quickly wears and breaks down the cutting tool.
Precision Machining Service
- EDM Machining
With years of experience in handling tungsten and molybdenum, our highly trained technicians are skilled in offering the above machining services for a variety of tungsten and molybdenum including unalloyed tungsten and molybdenum, tungsten heavy alloy, copper tungsten alloy, TZM alloy and molybdenum copper alloy, lanthanated molybdenum alloy, lanthanated tungsten alloy etc.,
Other Available Processes We Can Provide
Ductile to brittle transition temperature (DBTT) and recrystallization temperature are the two major factors that affect the forming process of tungsten and molybdenum materials. All of the forming such as bending, punching, forging, spinning and cutting must occur somewhere between these two ranges of temperatures. Tungsten becomes progressively brittle as the DBTI drops and more ductile as the recrystallization temperature rises. DBTI of tungsten materials is 200 – 500°C. Recrystallization temperature is 856 – 1200 °C. These temperature ranges are the upper and lower limits of the forming temperature.
The best working range of temperatures to machine tungsten and tungsten alloys is from 343 to 371°C. The copper and silver doped tungsten alloy and tungsten heavy alloy can be machined under room temperature. The tungsten materials with a relative density of 93% are the hardest to be machined. Therefore, the SiC or AL2O3 low-speed grinding is the typical method utilized to machine the materials. The tungsten materials with a relative density lower than 93% are comparatively easier to grind and cut by using wheels with high hardness (K or L) or ruby wheels.
Joining is an integrated process including one or diverse methods, such as riveting, induction welding, resistance welding, soldering and chemical vapor deposition.