R	indenter tip radius
r	distance from the center of cylindrical indenter
h	indenter penetration depth
σz	normal stress in z direction
τrz	shear stress in the rz plane
u z	displacement in z direction
P m	mean contact pressure
P max	maximum contact pressure
E	Young’s modulus
ν	Poisson’s ratio
(r, θ, z)	local cylindrical coordinate system
σr	normal stress in r direction
σθ	normal stress in θ direction
ξ	shear strength
Py	upper limit of the first plastic stage of the experimental pressure-penetration curve
σy	yield stress
P 0	initial pressure in stress relaxation tests
t	time
τ	relaxation time in stress relaxation tests
FIMEC	Flat top Indenter for Mechanical Characterization
IFMIF	International Fusion Materials Irradiation Facility
CFRP	Carbon Fiber Reinforced Polymer
DBTT	ductile to brittle transition temperature
CRB	cracked Round Bar
ISE	indentation size effect
PS	plasma spray
V W	volume fraction of W in the graded layers between CuCrZr substrate and pure W coating
x	distance from the pure W coating
t	interlayer thickness
p	gradient index
TIG	tungsten inert gas
MIG	metal-arc inert gas
GTAW	gas tungsten arc welding
HAZ	heat affected zone
MZ	molten zone
PWHT	post welding heat treatment
TBM	Test Blanket Module of ITER
ITER	International Thermonuclear Experimental Reactor
DSS	duplex stainless steel
SP	second phase
SEM	scanning electron microscopy
TEM	transmission electron microscopy