The planned research and development works are concerned with research issues that are related to the use of innovative laser technology (which belongs to the Additive Manufacturing group) and unique bronze layer used in order to refurbish rail wheel rims, and thus extending their life cycle up to 3 times. The analysis of the market environment shows that the lack of effective technologies used for refurbishment and protection of railway wheel rims is one of the current problems of rail transport, including railway transport (both in Poland and the EU). Currently used technologies of wheel rim refurbishment focus on re-profiling. The wear of railway wheel flanges caused by their contact with the rail head forces the use of this refurbishment method. It is widely used in order to restore the proper shape of the rim profile. Developing a technology that uses advanced laser methods common in laser deposition processes (one of the technologies being a part of Additive Manufacturing) shall enable an innovative refurbishment service of filling up the worn material at the wheel flange to be introduced into the market.
Appreciating the idea and the direction of our development, the EU has selected Plasma System to take part in the SME Instrument project, phase 1, to optimize the developed sliding layer.
Currently, the technology in question is on the 6th level of TRL. So far, basic subsystems of the technology have been verified, i.e. laser deposition and a unique layer of bronze. Internal tests and attempts to refurbish railway wheel rims have been conducted in laboratory conditions. This project shall constitute an expansion of the adopted approach to solving the identified market problems.
The main technological challenge that is concerned with the planned work and whose solution will determine the competitive advantages of the Project results is the selection of laser deposition technology and its optimization for railway wheel rims refurbishment, which shall significantly increase their durability. The very process of laser deposition optimizing is connected with carrying out a series of tests relating not only to robot programming, but also to the selection of a number of variable parameters, including the speed of the process, the amount of the powder to be fed, laser power, gas supply and the temperature of heating of the sample.
The elimination of minimal thermal stresses created during laser deposition shall constitute another important technological issue. It is expected that this challenge will be resolved by:
- maintaining the railway wheel rim in strict temperature regime for the entire duration of the laser deposition
- providing the deposited rim with ultrasounds of a specific frequency (about 24 +/- 2 KHz form a 12 kW generator
- induction heating of an area of 7 mm in diameter to a depth of 1.5 mm in the point of laser deposition
- producing preloads by stretching the rim from the inside for the duration of deposition and cooling of the rim.
This Project’s adopted method of resolving the main technological issue will lead to the desired result of the Project, i.e. technological readiness of smaRtAIL at the 9th level.
Innovative laser technology reconstruction and extend the durability of wheels contribute to reducing the problems identified.