Materials Joining with Metal-Hydrides
Metal Hydride Method for Details Joining
Tech Area / Field
- MAT-ALL/High Performance Metals and Alloys/Materials
- MAN-MPS/Manufacturing, Planning, Processing and Control/Manufacturing Technology
3 Approved without Funding
NPO Lutch, Russia, Moscow reg., Podolsk
Project summaryThe objecive of the Project is development of a new method of joining of parts made of perse materials in various combinations (metals, alloys, ceramics, cermet materials and so on), hardly or not connected by traditional methods of welding and soldering.
The technical approach is based on the preparation of space between connected parts, which is filled by intermediate metal or alloy forming hydride, and conducting the process of it hydriding in hydrogen atmocphere. During hydriding the intermediate insert is increased in volume of a space and provides pressure on its contact surfaces, ensuring joining of parts with each other.
Experiments have shown, that the value of contact pressure, created by intermediate hydride forming material, can be adjusted by parameters of hydriding process, and can reach values of tens MPa, ensuring diffusion welding of parts.
Diffusion processes during metalhydride welding due to creation of high contact pressure, can procced at lower temperatures, than during diffusion welding. As against diffusion welding, metalhydride welding will not require use of the power equipment for creation of mechanical pressure between connected parts.
The joining can be carried out as well without diffusion coupling, and their disasssembly is possible after dehydriding of an intermediate material. It allows simple replacement of worn out parts, their repair and other similar operations.
In order to develop joinings, intended for various conditions of operation, it is supposed to investigate a wide nomenclature of forming hydride metals and alloys as intermediate inserts and layers, capable to be hydrided in a range of temperatures from room up to 1000 °C.
During the Project fulfilment it is planned to solve the following scientific, engineering, and practical problems:
— choice of forming hydride metals and alloys, acceptable for realization metalhydride method of joining of parts made of perse materials (low-melting-point and refractory metals and alloys, ceramics and cermets);
— investigate the structural, physical and mechanical characteristics of received joinings;
— develop the technology of parts joining by metalhydride method for joining of various types of materials;
— make and test prototypes the joinings and give out the recommendations, allowing to estimate technical and economic prospects of joining.
The final result of the Project fulfilment should be creation of a new metalhydride method of joining of parts, which will allow to develop new kinds of designs of adapters, pressure-seal and current feed-through, gas-and vacuum-tight units, perse connections for products of hydrogen, vacuum, electrical and cryogenic engineering, chemical and heat technology installations, engines and so on, and also in a number of cases to replace traditional methods of welding and soldering.