Table 2.

Relevant parameters for dimensionless numbers.

Category	Variable	Symbol	Unit	SI Base Unit 1
process parameters	absorbed laser beam power	Pa	W	M∙L2∙T−3
	interaction time	τl	s	T
joint configuration	overlap width	wo	m	L
	thickness of metal sheet	tm	m	L
material properties of the metal	thermal conductivity	λm	W∙m−1∙K−1	M∙L∙T−3∙θ−1
	specific heat capacity	cp,m	J∙kg−1∙K−1	L2∙T−2∙θ−1
	density	ρm	kg∙m−3	M∙L−3
material properties of the polymer	thermal diffusivity	αp	m2∙s−1	L2∙T−1
	beginning of melting interval	Tim	°C	θ
	melting enthalpy	∆Hm	kJ∙kg−1	L2∙T−2
resulting molten zone	molten zone area	Ap	m2	L2
	molten zone width	wp	m	L
	molten zone thickness	dp	m	L

¹ SI base units: M–mass, L–length, T–time, θ–temperature.