I am willing to know about what are the materials used in the manufacturing of the Metro rail wheels. So is there any one who can give me the information about what are the materials used in the manufacturing of the Metro rail wheels? Give me the details of the Project for wheel-less trains on Delhi Metro?

A rubber-tyred metro is a form of rapid transit system that uses a mix of road and rail technology. The vehicles have wheels with rubber tires which run on rolling pads inside guide bars for traction, as well as traditional railway steel wheels with deep flanges on steel tracks for guidance through conventional switches as well as guidance in case a tyre fails

Rubber-tyres have higher rolling resistance when compared to traditional steel wheels, which leads to some advantages and disadvantages.

About the Technology : The vehicle is in the form of electric multiple unit, with power supplied by both, of the guide bars, which thus also serves as the third rail (the current is not picked up through the horizontal wheels, but through a separate lateral pickup shoe).

The return current passes through a return shoe to the top of one, or both of the rails, or to the other guide bar, depending on the type of system.


Advantages

MPL-85 rolling stock in Lyon métro.
Compared to steel wheel on steel rail, the advantages of rubber-tyred metro systems are:

Smoother rides (with little jostling around).
Faster acceleration and higher speed, along with the ability to climb or descend steeper slopes (~gradient 13%) than would be feasible with conventional rail tracks, which would likely need a rack instead.
For example, the rubber-tyred Line 2 of the Lausanne Metro has grades of up to 12%.

Shorter braking distances, allowing trains to be signalled closer together.
Quieter rides in open air (both inside and outside the train).citation needed
Greatly reduced rail wear with resulting reduced maintenance costs of those parts.

Disadvantages

NM-73 in Mexico City metro.
The higher friction and increased rolling resistance cause disadvantages (compared to steel wheel on steel rail):

Higher energy consumption.
Possibility of tyre blow-outs - not possible in railway wheels.
Hotter operation.
Weather variance. (Applicable only to above-ground installations)
Loss of the traction-advantage in inclement weather (snow and ice).
Heavier as steel rails remain for switching purposes, to provide electricity or grounding to the trains and as a safety backup.
Tyres which frequently need to be replaced; contrary to rails using steel wheels, which need to be replaced less often.
Creation of air pollution; tyres break down during use and turn into particulate matter, which can be dangerous