High-temperature insulators, boron nitride, furnace construction, PVD systems, surface technology

MYCROSINT^® BORON NITRIDE (BN) HIGH-TEMPERATURE INSULATORS FOR FURNACE CONSTRUCTION, PVD SYSTEMS, SURFACE TECHNOLOGY

The functionalization of the surface of materials has gained ever increasing importance in recent years. An extremely varied range of coating technologies is now available.

MYCROSINT^® – Insulation under Extreme Conditions

The technique now mainly used to apply abrasion-resistant, optical or decorative coatings to metal, glass or polymer substrates is physical vapor deposition (PVD), which offers a diverse range of applications and good environmental compatibility.

The substances to be coated are converted into the vapor phase at between 500°C and 1500°C, and then deposited on the lower temperature substrate. These processes require insulation materials such as ESK’s MYCROSINT^® boron nitride ceramic, which provides assured electrical insulation even under the most severe conditions. Furthermore, it is easy to remove any deposits on insulators resulting from the application process.

			Boron Nitride
Material properties	Norm	Symbol / Unit	MYCROSINT^® HD	MYCROSINT^® S		MYCROSINT^® CD
Crystalline phases			hex. BN	hex. BN		hex. BN
Binder phase / Binder type			<1%B₂O₃	4%B₂O₃		B₂O₃ + CaO
Orientation dependency			Isotropic	Anisotropic		Anisotropic
Orientation dependency				⊥	II	⊥	II
Density (typical)	DIN EN 623-2	ρ [g/cm³]	1.96	2.07	2.07	1.97	1.97
Total porosity (calculated using theoretical density)	DIN EN 623-2	P [%]	<13	<7	<7	<12	<12
Brinell hardness	DIN EN ISO 6506-1	HBW 2.5/31.25	10	30	30	13	13
Young’s modulus	DIN EN 843-2	E [GPa]	23	35	30	30	25
Flexural strength	DIN EN 843-1	σ_B [MPa]	19	95	85	40	35
Weibull modulus	DIN EN 843-1
Compressive strength	AAW/ AC-R-302-03	σ_D [MPa]	36	105	125	50	55
Coefficient of thermal expansion	DIN EN 821-1			Thermal expansion behavior: nonlinear, residual elonation after cooling; CTE given indication only
20°C - 500°C		α [10^-6/K]	-1	1	2	-1	-1
500°C - 1000°C		α [10^-6/K]	0.5	1	2	1.5	2
1000°C - 1500°C		α [10^-6/K]	2.5	1	5	3	4
Specific heat at 20°C	DIN EN 821-3	C_p [J/gK]	0.61	0.6	0.6	0.58	0.58
Thermal conductivity at 20°C	DIN EN 821-2	λ [W/mK]	25	40	25	35	35
Maximum temperature of use (oxidizing/inert atmosphere)		[°C]	900/1800	1000/ 1500	1000/ 1500	1100/ 1500	1100/ 1500
Specific electrical resistance at 20°C	DIN EN 50359	ρ [Ωcm]	>10¹²	>10¹²	>10¹²	>10¹²	>10¹²

			Boron Nitride
Material properties	Norm	Symbol / Unit	MYCROSINT^® SO20		MYCROSINT^® SO43		MYCROSINT^® O40
Crystalline phases			BN+ZrO₂+SiC		BN+ZrO₂+SiC		BN+ZrO₂
Binder phase / Binder type							2%B₂O₃
Orientation dependency			Anisotropic		Anisotropic		Anisotropic
Orientation dependency			⊥	II	⊥	II	⊥	II
Density (typical)	DIN EN 623-2	ρ [g/cm³]	2.3	2.3	2.92	2.92	2.82	2.82
Total porosity (calculated using theoretical density)	DIN EN 623-2	P [%]	10	10	<6	<6	<6	<6
Brinell hardness	DIN EN ISO 6506-1	HBW 2.5/31.25	30	30	85	85	63	63
Young’s modulus	DIN EN 843-2	E [GPa]	35	20	45	30	45	25
Flexural strength	DIN EN 843-1	σ_B [MPa]	70	40	120	80	120	80
Weibull modulus	DIN EN 843-1
Compressive strength	AAW/ AC-R-302-03	σ_D [MPa]	85	100	175	175	185	185
Coefficient of thermal expansion	DIN EN 821-1		Thermal expansion behavior: nonlinear, residual elonation after cooling; CTE given indication only
20°C - 500°C		α [10^-6/K]	0.5	4.6	2	8	2	6
500°C - 1000°C		α [10^-6/K]	1.9	6.6	4	9	3.5	9
1000°C - 1500°C		α [10^-6/K]	0.5	2.2	1.4	4.5	1.5	8
Specific heat at 20°C	DIN EN 821-3	C_p [J/gK]	0.6	0.6	0.5	0.5	0.5	0.5
Thermal conductivity at 20°C	DIN EN 821-2	λ [W/mK]	45	25	40	30	30	20
Maximum temperature of use (oxidizing/inert atmosphere)		[°C]	1100/ 1800	1100/ 1800	1100/ 1800	1100/ 1800	1100/ 1800	1100/ 1800
Specific electrical resistance at 20°C	DIN EN 50359	ρ [Ωcm]	>10¹²	>10¹²	>10¹²	>10¹²	>10¹²	>10¹²