The Experimental Study on Nitrogen Releasing Regularity and NO_x Reduction During the Coal Combustion
Post Date: 14 Oct 2010 Viewed: 766
The hard-brittle material is widely used in energy, information, manufacture, and architecture field. But low productive efficiency, bad surface integrity, rapid tools wear and high product cost hold back the wider application of hard-brittle material in modern industry.An electroplating diamond endless wire saw (EDEWS) with CW225 wire is reported in this paper. The experimental research and theoretical analysis on EDEWS is carried out with LT55 Al2O3/TiC ceramic. On cutting LT55 ceramics experiment, the highest velocity of wire is 13.08m/s, the highest cutting efficiency is 6.665mm2/min.and the roughness is between 0.247 and 0.352μm. The surface quality achieved fromEDEWS machining is superior to the one from circle saw or electron discharge machining (EDM).The indentation fracture mechanics approach and the machining approach on the grinding mechanisms for ceramics hold true in the EDEWS machining. According to the researching of cutting process, a EDEWS cutting model is set up. The formulas for average cutting depth of grain and for virtual cutting depth of grain are induced. The accommodation coefficient in formula for virtual cutting depth of grain is calculated by the test. The ceramics material mostly is cut off on brittle regime, but it is cut off on half-ductile regime at 14N drive weight, 5.23m/s velocity of wire.The micro-scale observes and finite element analysis (FEA) methods were employed to investigate the failure of wire. The diamond grits suffer four wear states: micro-fractured, macro-fractured, worn-flat and pull-out grain. The holes in welding area mainly cause the fatigued wire to break. The finite element analysis (FEA) implies that the highest stress occurs at the interface close to the surface of the plating layer. The highest tension stress results in the grit falling out. The magnitude of pulling stress at the tension side of the particle increase drastically when the plating layer is worn away.which accelerate diamond grits to Debond or fall out.