Title:	DFT investigations of ductility in transition metal nitrides
DNr:	SNIC 2014/1-338
Project Type:	SNIC Medium Compute
Principal Investigator:	Valeriu Chirita <vio@ifm.liu.se>
Affiliation:	Linköpings universitet
Duration:	2014-11-01 – 2015-11-01
Classification:	20501
Keywords:

Abstract

Brittleness limits the protective capability of hard transition metal nitrides (TMN) coatings. The investigators recently demonstrated how ductility can be improved in commonly brittle TMN by manipulating the electronic structure, while at the same time maintaining high hardness. The theoretical predictions have been validated at IFM by synthesizing a new material (VMoN), and testing its mechanical behavior. Many questions, however, are still to be answered. Dislocation movement (plastic deformation) plays a key role in determining ductility. The investigators intend to study how dislocation mobility is affected upon varying the electron concentration in supertough VMoN and other candidate tough TMN alloys. This will allow to understand at a fundamental level how ductility is increased while hardness is preserved. During last year, using the NSC resources, we published the following papers: APL Materials 1, 042104 (2013), TSF (in press, 2014)