Nondestructive Inspection of Thin Basalt Fiber Reinforced Composites Using Combined Terahertz Imaging and Infrared Thermography

Table 1

Selected properties of basalt and glass fibers [7, 8].

Properties	Unit	Basalt	E-Glass	S-Glass
Density	g/cm^3	2.7	2.57	2.48
Thermal linear expansion coefficient	ppm/°C	8.0	5.4	2.9
Tensile strength	GPa	4.84	3.45	4.71
Elastic modulus	GPa	89	77	89
Elongation at break	%	3.15	4.7	5.6
Compression strength	MPa	3792	3033	3033
Maximum application temperature	°C	982°	650°	650°
Sustained operating temperature	°C	820°	480°	480°
Minimum operating temperature	°C	−260°	−60°	−60°
Melting temperature	°C	1450°	1120°	1120°
Absorption of humidity (65% RAH)	%	<0.1	<0.1	<0.1
Emissivity at 20°C	—	0.92	0.65	0.65
Thermal conductivity	W/m K	0.031–0.038	0.034–0.04	0.034–0.04