Structure and Properties Modifications in Boron Nitride. Part I: Direct Polymorphic Transformations Mechanisms
نویسندگان
چکیده
S-a efectuat o examinare aprofundată a structurii varietăţilor polimorfe ale nitrurii de bor BN şi a mecanismelor tranziţiilor polimorfe de la structurile hibridizate sp la structurile hibridizate sp cu scopul de a explica pe baze cantitative modificarea dramatică a durităţii care face ca nitrura hexagonală de bor (grafitul alb) să fie un lubrifiant solid moale, în timp ce nitrura cubică de bor este un superabraziv situat al doilea după diamant ca duritate. In vederea scopului propus au fost luate în considerare numai transformările referitoare la tranziţiile polimorfe directe fără implicarea solvenţilor-catalizatori în cursul sintezei varietăţilor polimorfe hibridizate sp .
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