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- Install, training & calibration commissioned on site by Carbolite Gero service
- Validated first cycle atmosphere & soak profile dialed in for your alloy
Furnances, Atmosphere Controlled Ovens
Carbolite Gero HTMA Controlled Atmosphere Oven – Up to 700°C | 28–1000 L
Controlled atmosphere oven for metal AM post-processing and materials research — 400–700°C max (4 grades), 28–1,000 L chambers (5 sizes), O₂ down to 50 ppm with N₂/Ar purge. Seam-welded gas-tight chamber built as an atmosphere unit from the ground up.
- ✓ O₂ down to 50 ppm — atmosphere-controlled heat treatment without vacuum-furnace cost
- ✓ 17 configurations in one family — 28 L lab to 1,000 L production, same gas architecture
- ✓ Seam-welded gas-tight chamber — purpose-built, not a retort-converted standard oven
- ✓ Configured to order — request lead time; install, training & cycle validation included
Price held 7 days after order.
Install + training included
Tailored service plan
What your process engineer actually checks
What your process engineer actually checks
Atmosphere you can document
Oxygen down to 50 ppm under N₂ or Ar purge, with optional outlet O₂ monitoring logged per run via the Nanodac controller — the traceability an AS9100 or NADCAP heat-treatment record needs. Fully seam-welded chamber, no retort leak paths.
One recipe, 17 sizes
The same gas-control architecture runs from a 28 L bench oven to a 1,000 L production chamber. Prove a stress-relief or anneal cycle on the small oven, then transfer it to production without re-developing the process.
An applications engineer on the line
Not a remote ticket queue. We run heat treatment on LPBF titanium and stainless in-house at AO Metal — atmosphere, soak temperatures and ramp rates for your alloys, answered in under 24h. NDA standard.
About this product
The Carbolite Gero HTMA is a range of controlled-atmosphere ovens covering 400°C to 700°C in chamber volumes from 28 to 1,000 litres — 17 configurations in one family. The chamber is fully seam-welded and engineered as an atmosphere unit from the ground up, not a retort added to a standard oven. Under nitrogen or argon purge, internal oxygen down to 50 ppm is achievable, with optional real-time O₂ monitoring and closed-loop control via a Nanodac programmer. For metal additive manufacturing it is used primarily for post-processing — stress relief, annealing, and low-temperature solution treatment of Ti-6Al-4V, stainless, nickel, and copper alloys in an oxygen-controlled environment, without the cost or complexity of a vacuum furnace.
Why engineers choose the HTMA
Atmosphere-controlled heat treatment for oxidation-sensitive alloys — the spec figures below are from the Carbolite Gero datasheet.
O₂ down to 50 ppm
Nitrogen or argon purge reaches oxygen levels low enough for oxidation-sensitive alloys — Ti, Cu, stainless — without a vacuum system.
Seam-welded gas-tight chamber
Designed as an atmosphere unit and fully seam-welded to contain modified atmospheres — no leakage paths from a bolt-on retort interface.
17 configurations, one architecture
The same gas-control design scales from a 28 L bench oven to a 1,000 L production chamber, so a validated process recipe transfers directly between sizes.
Separate purge & process gas control
Independent flow controls purge atmospheric air, then run process gas at a lower rate. Manual needle valves as standard; automatic programmable control and outlet O₂ monitoring optional.
How we deliver it
Configured to order, installed, and validated by engineers who run heat treatment in-house.
Step 01
Configure to your process
Pick temperature grade (400–700°C), chamber volume, controller, and gas-control options — automatic control, stainless valves, flow-failure alarm, O₂ monitoring.
Step 02
Install & train on site
US-based delivery, installation, and operator training. Thermocouple calibration and gas-flow setup handled by Carbolite Gero service.
Step 03
Validate your cycle
We dial in atmosphere, soak temperatures, and ramp rates for the alloys you print — and can run your parts at AO Metal before the oven ships.
Temperature grades & chamber volumes
| Model | Max temp | Available chamber volumes |
|---|---|---|
| HTMA 4/x | 400°C | 28, 95, 220, 500, 1000 L |
| HTMA 5/x | 500°C | 28, 95, 220, 500, 1000 L |
| HTMA 6/x | 600°C | 28, 95, 220, 500, 1000 L |
| HTMA 7/x | 700°C | 28, 95, 220 L |
Minimum operating temperature is approximately ambient +60°C. Full per-model heat-up times, dimensions, shelf loading, and power ratings are in the Specifications tab and the datasheet below.
Typical applications
Where the HTMA earns its place in an AM and materials workflow.
Metal AM stress relief
Ti-6Al-4V, 316L, 17-4PH, Inconel 625/718 in Ar
Annealing & solution treatment
Hardened AM steels, copper & nickel alloys
Battery research
Electrode calcination, cathode synthesis
Materials science R&D
Pyrolysis, phase-transformation, sintering trials
Electronics processing
PCB bake-out, solder-glass, component annealing
Not sure the HTMA is the right oven?
If you don’t need an inert atmosphere, a simpler Carbolite Gero oven from the same family may be a better fit.
No inert atmosphere neededHT Industrial OvenView oven →Particle-clean, not gas-inertHTCR Clean Room OvenView oven →General lab heatingPF Laboratory OvenView oven →
Tell us your alloy, part size, and target soak temperature — our applications engineer will confirm the right temperature grade, chamber volume, and gas-control options, and can validate the cycle on your parts at AO Metal first. Configurations are priced per specification.
Why source through Additive Plus
- AM heat-treatment expertise — atmosphere selection, soak temperatures, ramp rates, and quench paths for the alloys you’re printing; not just oven delivery.
- In-house heat treatment at AO Metal — we run post-processing on LPBF titanium and stainless parts and can validate your cycle before the equipment ships.
- US-based support and consumables — Carbolite Gero service, spares, and thermocouple calibration handled locally.
- Leasing and financing available — with a sub-24h engineer response on every enquiry.
HTMA — Product Overview
| Brand | Carbolite Gero |
| Model (representative) | HTMA 6/28 |
| Max temp | 600°C (family: 400–700°C) |
| Volume (litres) | 28 (family: 28–1000 L) |
| Atmosphere | N₂ / Ar purge — O₂ down to 50 ppm |
| Heat-up time (mins) | 60 |
| Recovery time (mins) | 10 |
| Dimensions: Internal H x W x D | 12.01 × 12.01 × 12.01 in / 305 × 305 × 305 mm |
| Dimensions: External H x W x D | 38.98 × 31.89 × 34.84 in / 990 × 810 × 885 mm |
| Shelves fitted / accepted | 2 / 2 |
| Shelf loading each / total (kg) | 10 / 20 |
| Max power (W) | 2000 |
| Weight (kg) | 73 |
Product videos
Want proof before you commit?
Send us your printed parts and target spec. We'll run a paid trial stress-relief or anneal cycle under controlled atmosphere at AO Metal in California and share the results before you specify an oven.
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From production teams running Carbolite Gero HTMA Controlled Atmosphere Oven – Up to 700°C | 28–1000 L
Unedited feedback from teams who bought and run Carbolite Gero HTMA Controlled Atmosphere Oven – Up to 700°C | 28–1000 L.
★★★★★
Sinter profile was validated on our material at install. Shrinkage is predictable build after build.
MK
Marcus K.
Process Engineer · Metal AM
★★★★★
Asked about debind for a thick section. An engineer sent the actual schedule, not a generic chart.
PS
Priya S.
R&D Lead · Medical Devices
★★★★★
Ran our parts through their furnace as a service first. Density hit spec, so we bought the unit.
DR
Diego R.
Production Lead · Energy
Common questions
Don't see yours? Email [email protected] — NDA standard, typical reply within 4 hours.
What oxygen level can the HTMA reach, and how?
The HTMA achieves internal oxygen down to 50 ppm under a nitrogen or argon purge. Separate flow controls purge atmospheric air from the chamber first, then run process gas at a lower rate to hold the atmosphere. An optional oxygen sensor on the gas outlet displays the level in ppm or percent, and with a Nanodac controller the O₂ trace can be logged per run — useful for AS9100 or NADCAP heat-treatment records.
What temperature grades and chamber sizes are available?
The HTMA family covers four maximum-temperature grades — 400°C, 500°C, 600°C and 700°C — across chamber volumes of 28, 95, 220, 500 and 1,000 litres. The 700°C grade is offered in 28, 95 and 220 L; the other grades cover all five sizes, for 17 configurations in total. Minimum operating temperature is roughly ambient +60°C. All share the same gas-control architecture, so a validated cycle transfers between sizes.
Can it heat-treat metal AM parts without oxidation?
Yes. Under argon or nitrogen at 50 ppm O₂, the HTMA runs stress relief, annealing and low-temperature solution treatment on Ti-6Al-4V, 316L and 17-4PH stainless, Inconel 625/718 and copper alloys without the surface oxidation you would get in an air oven. It covers the temperature range most LPBF stress-relief cycles need (typically 400–650°C for stainless and nickel) — confirm your alloy's target soak with our applications engineer.
Is automatic gas control and oxygen monitoring standard or optional?
Standard HTMA ovens ship with manual gas control via needle valves and flowmeters, and a Carbolite 301 controller with single ramp-to-setpoint and process timer. Automatic programmable gas control, outlet oxygen monitoring, stainless steel valves and flowmeters, a flow-failure alarm, and multi-segment programmers (with RS232/RS485/Ethernet) are options specified at time of order. Oxygen monitoring is available with Nanodac instruments. We help you spec the right control package for your process.
How does the HTMA compare to a vacuum furnace for stress relief?
For low-temperature stress relief and annealing of oxidation-sensitive alloys, an inert-atmosphere oven like the HTMA reaches an oxygen level low enough to prevent scaling at a fraction of the capital cost and complexity of a vacuum furnace — no pumps, no vacuum-tight hot zone, simpler operation. A vacuum furnace is the right tool when you need higher temperatures, very low residual gas, or brazing/sintering. For most AM post-build stress relief up to 700°C, the HTMA is the practical choice.
What gas supply and infrastructure does it require?
The HTMA connects to a nitrogen or argon supply through a bulkhead compression fitting sized for 10 mm outside-diameter tube, at a maximum inlet pressure of 2 bar. Power depends on the model — from 2 kW on the 28 L up to 24 kW on a 600°C 1,000 L unit — with heat-up figures rated on a 240 V supply. Fixed or castor-mounted floor stands are available for the larger chambers. Our team confirms gas, power and footprint before delivery.
What lead time, installation and support come with the oven?
Because the HTMA is configured to order across 17 sizes and several control options, lead time is quoted per specification — request it with your configuration. Additive Plus provides US-based delivery, installation and operator training, Carbolite Gero service and spares, and thermocouple calibration locally. Leasing and financing are available for capital equipment, with a sub-24h engineer response on every enquiry.
Does Additive Plus help validate the heat-treatment cycle?
Yes. We run heat treatment on LPBF titanium and stainless parts in-house at AO Metal, so we can recommend atmosphere, soak temperature and ramp rate for your alloy — and run a paid trial cycle on your actual printed parts before you specify an oven. That way the configuration you buy is matched to a process you have already seen results from.
Place your order, or talk to an engineer first
Order Carbolite Gero HTMA Controlled Atmosphere Oven – Up to 700°C | 28–1000 L direct, or talk to materials engineer