CVD Diamond (Optical) TM
Print state
TM = thermal management grade polycrystalline CVD diamond heat spreader
Choose for laser-diode and RF/GaN heat spreaders where thermal conductivity and metallisability matter but optical clarity does not.
Values for the TM condition
Other CVD Diamond (Optical) tempers and conditions
CVD Diamond (Optical) is listed in 3 conditions; see the grade overview at CVD Diamond (Optical).
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
TMThis page Thermal management grade polycrystalline CVD diamond heat spreader | Choose for laser-diode and RF/GaN heat spreaders where thermal conductivity and metallisability matter but optical clarity does not. | — | 350 | 0.03 | — | 1,800 W/m·K |
Mechanical / tool grade thick polycrystalline CVD diamond | Choose for cutting-tool inserts, wire-drawing dies, wear parts and probe tips where strength and wear life beat optical purity. | — | 500 | 0.05 | — | 1,300 W/m·K |
Single-crystal CVD diamond | Choose for small apertures needing zero grain-boundary scatter: Raman lasers, X-ray optics, anvils, radiation detectors and quantum devices. | — | — | — | — | 2,200 W/m·K |
What is CVD Diamond (Optical) TM?
CVD Diamond (Optical) TM is CVD Diamond (Optical) in the TM condition — choose for laser-diode and RF/GaN heat spreaders where thermal conductivity and metallisability matter but optical clarity does not. CVD Diamond (Optical) TM has a tensile strength of 350 MPa (50.8 ksi), stronger than 91% of glass grades. The elastic modulus is 1,100 GPa (159.5 Msi). CVD Diamond (Optical) TM has a density of 3.51 g/cm³ (0.127 lb/in³), heavier than 67% of glass grades. It melts at 3,550°C (6,422 °F).
Advantages
- Stiff — 1,100 GPa (159.5 Msi), better than 100% of glass grades
- Tough — resists crack growth — 5.5 MPa·√m (5.01 ksi·√in), better than 100% of glass grades
- Conducts heat well — 1,800 W/m·K (1,040 BTU/hr·ft·°F), better than 100% of glass grades
- Good corrosion resistance — 99/100, better than 100% of glass grades
Limitations
- Difficult to machine — 1/100, worse than 100% of glass grades
CVD Diamond (Optical) TM properties
Typical room-temperature values for CVD Diamond (Optical) TM; 14 are specific to this condition. Other listed values are CVD Diamond (Optical) reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
CVD Diamond (Optical) TM has a density of 3.51 g/cm³ (0.127 lb/in³), heavier than 67% of glass grades. It melts at 3,550°C (6,422 °F).
Mechanical10
CVD Diamond (Optical) TM has a tensile strength of 350 MPa (50.8 ksi), stronger than 91% of glass grades. The elastic modulus is 1,100 GPa (159.5 Msi).
Thermal5
CVD Diamond (Optical) TM is rated for continuous service to 600°C (1,112 °F). It conducts heat at 1,800 W/m·K (1,040 BTU/hr·ft·°F), better than 100% of glass grades. Thermal expansion is 1.1 µm/m·K (0.611 µin/in·°F).
Electrical4
CVD Diamond (Optical) TM has an electrical resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (99/100), better than 100% of glass grades.
Sustainability1
Typical recycled content is 0%.
Manufacturability2
CVD Diamond (Optical) TM's machinability is not recommended (1/100, worse than 100% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CVD Diamond (Optical) TM
Is CVD Diamond (Optical) easy to machine?
No conventional machining — shaping is by pulsed laser cutting/drilling, then lapping and scaife or ion-beam polishing with diamond grit.
Can CVD Diamond (Optical) be welded?
Cannot be welded; joined by active brazing with Ti/Cr-containing filler (TiCuSil) below ~850 °C in vacuum, or by metallised (Ti/Pt/Au) solder joints.
Can CVD Diamond (Optical) be formed, bent or molded?
Grown near-net-thickness as free-standing plate by microwave-plasma or hot-filament CVD on Si/Mo substrates at ~700–1000 °C, then laser-trimmed; wafer sizes typically up to ~150 mm.
What surface finishes work on CVD Diamond (Optical)?
Polished to <5 nm Ra on both faces; single- or dual-band AR coatings (or laser-machined moth-eye surface structures) raise transmission from ~71 % to >98 %.
CVD Diamond (Optical) chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Nsubstitutional nitrogen, typically <1 ppm in optical grade | ≤ 5×10⁻⁴ | 5×10⁻⁵ |
| Hhydrogen bonded at grain boundaries from the CH4/H2 growth chemistry | ≤ 0.01 | 0 |
| Sitrace, from reactor window/holder (SiV centre) | ≤ 2×10⁻⁴ | — |
| Btrace unless intentionally doped for conductive grades | ≤ 5×10⁻⁵ | — |
| Csp3 diamond carbon; non-diamond (sp2) content kept below Raman detection in optical grade | ≥ 99.95 (balance) | — |
CVD Diamond (Optical) TM — frequently asked
What is CVD Diamond (Optical) TM used for?
CVD Diamond (Optical) TM is typically used for high-power CO2 laser windows, gyrotron windows, IR sensor domes and extreme-environment optics. In short: widest optical transmission range; highest thermal conductivity window; hardest optical material.
What is the tensile strength of CVD Diamond (Optical) TM?
CVD Diamond (Optical) TM has a typical tensile strength of 350 MPa (50.8 ksi) — stronger than 91% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is CVD Diamond (Optical) TM easy to machine?
Not especially — machinability is rated not recommended (1/100, worse than 100% of glass grades). No conventional machining — shaping is by pulsed laser cutting/drilling, then lapping and scaife or ion-beam polishing with diamond grit.
Can CVD Diamond (Optical) TM be welded?
Cannot be welded; joined by active brazing with Ti/Cr-containing filler (TiCuSil) below ~850 °C in vacuum, or by metallised (Ti/Pt/Au) solder joints.
What surface finishes work on CVD Diamond (Optical) TM?
Polished to <5 nm Ra on both faces; single- or dual-band AR coatings (or laser-machined moth-eye surface structures) raise transmission from ~71 % to >98 %.
Can CVD Diamond (Optical) TM be formed, bent or molded?
Grown near-net-thickness as free-standing plate by microwave-plasma or hot-filament CVD on Si/Mo substrates at ~700–1000 °C, then laser-trimmed; wafer sizes typically up to ~150 mm.
What is the maximum service temperature of CVD Diamond (Optical) TM?
CVD Diamond (Optical) TM is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Diamond material properties — optical, thermal and mechanical grades — Element Six (2023)
- CVD Diamond Optics and Heat Spreaders — Coherent / II-VI Diamond (2023)
- ASM Engineered Materials Handbook Vol.4: Ceramics and Glasses — ASM International (1991)
- CRC Handbook of Chemistry and Physics — CRC Press (2020)
- Optical constants and transmission data for diamond — refractiveindex.info / Handbook of Optical Constants of Solids (1998)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.