Physical property

Physical properties

		Diamond	PCD (Sintered Diamond)	Sapphire/Ruby	Cemented carbide	Alumina	Zirconia	Quartz glass
Physical Properties	Composition	C	C＋binder	Al₂O₃	WC+Co	Al₂O₃	ZrO₂	SiO₂
	Specific Gravity	3.515	3.9～4.1	3.98	14.7～15.1	3.6～4.1	6.0～6.1	2.2
	Structure	Cubic crystal	Sintered body	Hexagonal crystal	Sintered body	Sintered body	Sintered body	Amorphous
Mechanical Properties	Tensile Strength GPa	1～4	1.3	0.5	0.8～1.7	0.12～0.21	0.14	0.05
	Flexural Strength GPa	N.A.	1.1～2.6	0.5～0.7	2.4～2.6	0.2～0.7	0.8～1.7	0.06
	Compressive Strength GPa	6～11	6.9～7.6	3.0～3.4	6.1	2.5～4.4	2.9～3.9	1.1
	Young's Modulus GPa	1,000～1,100	776～920	350～470	620～640	260～380	180～220	72～82
	Firmness	HK 6,000～11,000	HV 6,000～12,000	HK 1,500～2,000	HK 1,700	HV 1,000～2,300	HV 1,200～1,500	HK 590～ 620
Thermal Properties	Thermal conductivity W/(m･K)	600～2,000	400～500	40	80	17～33	1.7～2.9	1.3
Thermal Properties	Coefficient of Linear Expansion 10^-6/K	1～4	4～6	5～9	5	7～8	8～10	0.4～0.6
Electrical Properties	Electrical Resistivity Ω･m	10⁶～10¹⁸	1.4×10^-4 (Electrical discharge machining is possible)	10⁶～10¹³	10^-7	10¹²～	10¹²～	10¹²～
Optical Properties	Refractive Index (589.3nm)	2.417	-	C-axis⊥ 1.768	-	-	-	1.458
Optical Properties	Refractive Index (589.3nm)	2.417	-	C-axis∥ 1.760	-	-	-	1.458

Conversion Expressions：　1kgf/mm2=0.0098GPa、1dyn/cm2=0.1Pa、1cal/(cm･sec･℃)=418.4W/(m･K)

※The above properties are not guaranteed. These data should not be specified as engineering requirements or used for design purposes.