A,B,C, n, m	Model constants
Tm, Tr	Melting and reference temperatures
Smax	Peak compressive stress
Rma	Area fraction of matrix
Rcm	Area fraction of microbubbles/balloons
χy	Matrix yield strength
Zf	Fracture strength of bubble wall
Davg	Average bubble diameter
tw	Average wall thickness of the bubble
Ew	Bubble crush strength
cmf	Bubble volume fraction
rpar	Average radius of the bubble
St	UTS of the matrix material
	Tool rake angle
φ	Shear angle
p	Equivalent plastic strain
b	Width of cut
w	Undeformed chip thickness
¶	Chip compression ratio
STo	Tool shear strength
SPL	Specific energy for plastic deformation
Cthb	Three-body friction
Ctb	Two-body friction
uthb	Coefficient of friction
nthb	Normal force due to three-body rolling
Ï	Probability of bubbles engaged in abrasion