{HEAD ~ Boron} and carbon may be used as {TAIL ~ traditional sintering aids}, with nitrogen to suppress grain growth, and additions of yttrium and lanthanide elements to promote intergranular fracture 
used as
{ HEAD ~ Boron } and carbon may be used as { TAIL ~ traditional sintering aids } , with nitrogen to suppress grain growth , and additions of yttrium and lanthanide elements to promote intergranular fracture
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH