Continuing collaborative efforts for the technological advancement of manufacturing processes, Mazak Corporation and Oak Ridge National Laboratory’s (ORNL) manufacturing demonstration centre in Oak Ridge, TN, USA have entered into a cooperative research and development agreement (CRADA). Working on behalf of the US Department of Energy, ORNL and Mazak will further develop the use of Hot Wire Deposition (HWD) in additive manufacturing (AM) part production operations.
The project addresses Mazak’s HYBRID Multi-Tasking HWD technologies as a commercially viable solution which, upon completion, will result in a closed-loop control system featuring the ability to make on-the-fly adjustments according to sensor feedback during the HWD builds.
“Such in-process adjustability will further ensure the consistency, quality and reliability of HWD additive technology, especially for those manufacturers in the aerospace, automotive and die/mould industries, among others,” said a spokesperson.
Specific applications include the repair of turbine blades and other high-wear parts such as engine blocks, cylinder heads and moulds and dies. With the ability to build up worn or damaged parts and re-finish them on the same machine, manufacturers can increase the working lives of those parts and avoid the cost of producing new ones.
In operation, the closed-loop system will monitor and control the HWD melt pool temperature. As new layers are formed/built, temperatures of the initial layers cool as more layers are built above them. Conversely, as the HWD build continues, overall process heat levels also gradually increase as compared with those at the start of the build. For both scenarios, the control system will vary the laser intensity – higher or lower – to maintain consistent temperatures.
Through their collaborative research, Mazak and ORNL plan to generate an HWD process guide that will provide parameters for not only the process itself, but also for different metals. Mazak will then incorporate these parameters as a database into the control of the machine tool to automate the HWD process.
“As a pioneer in multi-tasking machine tool technology, Mazak recently advanced the concept with the development of its hybrid multi-tasking machines that combine additive technologies, such as direct metal laser sintering and multi-laser HWD, with subtractive manufacturing operations,” said the spokesperson.
Other hybrid systems combine conventional machining with joining capabilities such as friction stir welding and specialty operations like gear cutting. These hybrid systems are designed to advance Mazak’s multi-tasking Done-In-One part processing concept to the next level for increased single- machine production.
Mazak developed its initial hybrid HWD technology in partnership with Lincoln Electric. The two companies collaborated to combine Lincoln’s HWD process to that of Mazak’s multi-tasking subtractive (conventional machining) manufacturing technology.
“While Lincoln Electric can grow parts, their system is unable to finish the part,” said the spokesperson.
Mazak’s VC 500A/5X HWD (hot wire deposition machine) uses a laser head to grow part features, then exchanges that head for a milling one to finish machine the feature to specifications and generate a smooth surface finish to complete the part.
The machine’s hot wire laser cladding head incorporates an automatic wire feeder system that feeds welding wire to an Argon gas nozzle. The head delivers a deposition rate of three to four pounds per hour with a 98% material utilisation rate.
The VC-500A/5X HWD has a trunnion-style rotary/tilt table for the processing of small complex parts via full 5-axis machining. The machine also features the MazatroL SmoothX CNC and MTConnect capability that allow for easier programming and faster part cycle times – in either EIA or Mazatrol conversational language – along with digital connectivity.
Mazak’s VC-500A/5X AM HWD multi-tasking machine reduces lead times and part costs, increases machining accuracy and part quality, and improves productivity, according to the company.
For more information contact Hi-Tech Machine Tools on TEL: 011 608 0088 or visit www.hitech.co.za