Harder and stronger, yes. Stiffer, no. Harder chainrings will last longer, because the teeth will not wear down as quickly and become "shark's teeth." As to strength, you will never get close to breaking a track chainring, regardless of the alloy used or heat treatment. More important is that real track cranks are 144mm bcd, such that the radial distance from the bolt circle to the chainring teeth is smaller, making them stiffer. If you want the stiffest setup, then go with a smaller chainring and cog. For example, I used to race with a 50 x 15 combination, but now use 47 x 14 for racing, which is the same gearing.