The amount of carbon distributed over the surface of {HEAD ~ the silicon} carbide may be less than is typically used when {TAIL ~ boron} is the only other additive since Al metal is also added and also reacts with surface silica to remove it and promote sintering 
The amount of carbon distributed over the surface of { HEAD ~ the silicon } carbide may be less than is typically used when { TAIL ~ boron } is the only other additive since Al metal is also added and also reacts with surface silica to remove it and promote sintering
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH