TY  - EJOU
AU  - Li, Mao 
AU  - Tian, Xiaobao 
AU  - Jiang, Wentao 
AU  - Wang, Qingyuan 
AU  - Fan, Haidong 

TI  - Mechanism	of	Strain	Hardening	Of	Magnesium	Single-Crystals: Discrete	 Dislocation	Dynamics	Simulations
T2  - The International Conference on Computational \& Experimental Engineering and Sciences

PY  - 2023
VL  - 25
IS  - 2
SN  - 1933-2815

AB  - Poor	ductility	heavily	limits	the	industrial	application	of	magnesium	(Mg)	alloys,	and	pyramidal dislocations	
are	an	important	deformation	mode	for	ductility	enhancement.	In	this	work,	discrete dislocation	dynamics	
(DDD)	simulations	were	performed	to	study	the	mechanical	behavior	and dislocation	evolution	of	Mg	singlecrystals	compressed	along	c-axis.	Especially,	basal-transition and	cross-slip	algorithms	of	pyramidal	<c+a>	
dislocations	 were	 proposed	 and	 introduced	 in the	 DDD	 method.	 Simulation	 results	 show	 that	 basaltransition	is	an	important	mechanism	for	the strong	strain	hardening	observed	during	c-axis	compression	
of	Mg	single-crystals.	Since	the	basal-transition events	are	thermally	activated,	increasing	temperature	leads	
to	a	high	strain	hardening rate.	During	 the	deformation,	 the	<c+a>	dislocations	on	 first-order	pyramidal	
planes	mostly cross	slip	onto	second-order	pyramidal	planes	and	few	are	transited	onto	basal	planes,	while
<c+a>	dislocations	 on	 second-order	pyramidal	planes	are	mostly	 transited	 onto	basal	planes directly.	 In	
addition,	 the	basal-transition	behavior	is	an	important	reason	 for	 the	 formation	of dislocation	loops	and	
dislocation	steps	observed	in	experiments.	The	current	work	provides	new mechanisms	for	the	pyramidal	
dislocations,	which	are	significant	for	understanding	the	behaviors of	pyramidal	dislocations	and	ductility	
enhancement	of	Mg	alloys.
KW  - Dislocations;	magnesium;	dynamics;	strengthening	and	mechanisms;	crystal	plasticity

DO  - 10.32604/icces.2023.09981