Two blocks arrived in the inquiry: one a 737mm diameter disk at 137 kg, the other a 355mm × 610mm cylinder at 147 kg. Both in as-pressed condition. The customer needed OD profiling, face cuts, disk slicing, cross-cuts into 150mm tiles, and fine shrink bars — all from the same material, all with recorded cycle times on the cylinder. Their current equipment handled slicing only. Everything else was a problem.
This is a detailed walkthrough of how we approached that as-pressed ceramic cutting job: what the material state means for process planning, how we selected a single machine for all five operation types, what parameters we recommended, and where the approach still has real limits.
What As-Pressed Ceramic Cutting Is — and Why It’s Different from Sintered
“As-pressed” means the block has been powder-pressed to near-net shape and is still in its green body state — binder intact, not yet through final sintering. Density is lower than the fired part, hardness is lower, and the internal structure tolerates more cutting force before cracking.
For diamond wire cutting, that combination is favorable. Feed rates on as-pressed ceramic cutting jobs typically run 3–5× faster than on the same material post-sinter. Edge chipping risk drops considerably. Wire consumption per unit volume of material removed is lower because the abrasive doesn’t have to work as hard.
That doesn’t mean as-pressed blocks are easy to cut. The challenge isn’t hardness — it’s scale and geometry. A 147 kg cylinder that needs OD profiling, bisecting, and 20mm thin-slicing is a different engineering problem than a 50mm optical glass sample. The material cooperates; the machine has to be chosen carefully.
One thing worth flagging early: as-pressed blocks vary. Not all pressed ceramics or composites behave identically at this stage. Material density, binder type, and green body porosity all affect how the wire interacts with the surface. The parameters in this article are a starting point — final values need to be confirmed on the actual material in a test cut.
The Cutting Brief: Two Blocks, Twelve Operations
The customer specified a complete cutting sequence for both blocks. This wasn’t a single-pass slicing job — it was a multi-stage process that required five distinct motion types across two workpieces.
Block 1 — Disk: 29″ OD × 5.5″ Thick (≈ 737mm × 140mm, 137 kg)
The sequence:
- OD contour trim: Reduce outer diameter from 737mm to 686mm, removing 50mm radially to create a straight-wall cylinder
- Test face cut: Remove a 20mm discard slice from one face — this exposes a clean reference surface and leaves 120mm of usable thickness
- 15mm disk ×2: Two straight-feed slices at 686mm diameter
- 20mm disk ×1: One slice at 686mm diameter
- 25mm disk ×1: One slice at 686mm diameter
- Secondary cross-cut: Take the 25mm disk and grid-cut it into 150mm × 150mm square tiles
- Tertiary bar cut: Take one 150mm × 150mm tile and slice it into fine shrink bars
Seven operations, three different geometries, all on one 137 kg block. Any machine that only does straight feed slicing fails at step one.
Block 2 — Cylinder: 14″ OD × 24″ Long (≈ 355mm × 610mm, 147 kg)
This block was also the efficiency benchmark. The sequence:
- Test face cut: Remove 20mm discard slice from one end — usable length becomes 590mm
- OD contour trim: Reduce diameter from 355mm to 305mm
- Bisect: Split the cylinder lengthwise into two half-rounds, each 150mm high × 590mm long
- Timed thin-slice test: Take one half-round and cut it into 20mm thick sections — recording elapsed time for every single pass
That last requirement is what makes this more than a sample cut. The customer is building a throughput model. Each timed pass through a consistent geometry gives them a reliable data point for projecting cycle time at production volume. If they can’t hit their target machine hours per batch with this data, they’ll redesign the process before buying equipment.
Why As-Pressed Ceramic Cutting Needs a Multi-Function Machine
The obvious approach to a job like this is to route different operations to different machines: one for OD profiling, one for slicing, one for secondary cross-cuts. We’ve seen this done, and the results are predictable — alignment errors accumulate at every transfer, handling a 147 kg block between three stations introduces safety and repeatability risk, and setup time multiplies.
For as-pressed ceramic cutting at this scale, a single multi-function machine isn’t a convenience — it’s a process quality decision.
The operation types required here span four distinct motion categories:
- Découpe de contour (OD profiling of cylinder and disk)
- Linear feed slicing (disk cuts, face cuts, 20mm thin slices)
- Indexed cross-cutting (grid cuts into 150mm × 150mm tiles)
- Rotary-indexed cutting (bar cuts requiring workpiece rotation between passes)
A machine that can do all four keeps the workpiece on one datum throughout. Every operation references the same fixturing origin. Dimensional error doesn’t stack across transfers.
The SHI 100-R: One Table, All Five Operation Types
We recommended the SHI 100-R for this as-pressed ceramic cutting job. Here’s the specific capability match:
Contour cutting to Ø650mm. The SHI 100-R’s contour function programs the wire to follow a defined toolpath around the workpiece perimeter. For the 355mm cylinder needing a 50mm OD reduction, this is a single programmed contour pass — no lathe, no separate setup. The wire removes material along the profile and leaves a geometrically consistent outer surface.
Fair warning: contour cutting on a large cylindrical block demands solid fixturing. The workpiece must be centered accurately before the contour pass starts. We’ve had jobs where a 2mm center offset on a 300mm cylinder produced a final OD that was 2mm eccentric — not enough to see by eye during setup, but enough to cause problems at the next operation. Dial indicator check before every contour pass, every time.
Linear feed slicing. After profiling, the machine switches to standard Y-axis feed mode. Face cuts, the four disk slices, and the 20mm thin slices on the half-round all run as linear feed operations. No workpiece transfer, no re-fixturing. Same table, same origin.
Indexed cross-cutting for tile production. The 25mm disk cross-cut into 150mm × 150mm tiles is a two-perpendicular-pass operation. The SHI 100-R handles this directly on the work table. Index the workpiece 90°, run the second set of passes. The result is consistent tile dimensions because position error doesn’t accumulate between operations.
Rotary axis for bar cuts. The integrated rotary axis is what enables the shrink bar cuts without moving the workpiece off the table. Rotate the tile to the next angular position, run the pass, repeat. All referenced from the same fixture datum.
The total outcome: OD profile → face cut → disk slices → cross-cuts → bar cuts — one operator, one machine, one continuous setup. For a 147 kg block, not moving it between machines also means not dropping it, not re-clamping it wrong, and not spending 45 minutes re-indicating it every time.
On bisecting the cylinder: This operation — splitting the 355mm cylinder lengthwise into two half-rounds — is a contour pass along the center axis. The cylinder sits on its end, the wire runs a straight path through the centerline. Setup is simple in principle, but the cylinder must be perfectly level before locking down. Any tilt along the axis and the bisect plane drifts — your two half-rounds come out different heights at one end. We’ve seen a 1.5° tilt produce a 16mm height difference across a 600mm cylinder length. Check the axial level with a precision level or indicator before clamping, not after.
What Parameters Work for As-Pressed Ceramic Cutting?
Because this material is in the green body state, its cutting behavior sits between a pressed ceramic composite and a semi-sintered part. Lower hardness means more feed rate flexibility, but “flexible” doesn’t mean “anything goes” — especially on a 686mm OD contour pass where wire bow matters more than on a small flat slice.
Starting parameter ranges for as-pressed ceramic cutting at this block scale:
| Paramètre | Recommended Starting Range |
|---|---|
| Diamètre du fil | 0.55 – 0.80 mm |
| Tension du fil | 130 – 170 N |
| Vitesse du fil | 35 – 55 m/s |
| Feed Speed — Contour / Bisect | 5 – 8 mm/min |
| Feed Speed — Straight Slices | 10 – 20 mm/min |
| Refroidissement | huile minérale blanche |
A few specific notes from working with similar materials:
Separate your feed speed targets by operation type. Contour passes and bisect cuts involve continuously changing wire contact geometry — the effective cut depth per unit of feed travel changes as the wire moves around the curve. Start conservative at 5 mm/min and watch for wire bow on the exit side of the contour. Straight disk slices are predictable and repeatable; once you’ve confirmed surface quality on the first pass, 15–18 mm/min is achievable on 15–25mm thick slices.
Tension matters more than wire speed on long cuts. A wire running at 130 N through a 305mm half-round will develop visible bow by the midpoint of a slow cut. That bow translates to a curved slice face — measurable deviation from flat, which affects the customer’s downstream use of the tiles. Running 160–170 N keeps the wire straighter across the full cut length. You trade some wire life for dimensional consistency. On as-pressed material, that trade is worth it.
White mineral oil outperforms water-based coolant here. The as-pressed material generates fine powder-like debris — similar to what you see cutting isostatic graphite, not the larger chips you get from dense sintered ceramics. Water-based coolants tend to suspend that powder and recirculate it through the cutting zone. Mineral oil carries it clear more effectively and leaves a drier, cleaner cut surface. Filter the oil tank after every major operation change.
What Does the Timed Slice Test Actually Tell You?
The customer’s requirement to log cut time on every 20mm pass through the half-round cylinder is the most useful data this test will produce.
Here’s how to use it: measure elapsed time per pass, confirm feed rate from the machine controller, and calculate effective material removal rate as (pass thickness × cross-section area) ÷ time. Do this across 5–8 consecutive passes. If the rate is consistent, the wire is performing steadily. If it degrades noticeably by pass 6 or 7, you’re seeing wire wear in real time — useful for estimating wire replacement frequency at production volume.
Pour as-pressed ceramic cutting compared to fully sintered equivalents, the throughput advantage is real and significant. In our experience with similar green body materials, effective removal rate runs roughly 3–4× higher than post-sinter. On a batch of 147 kg cylinders, that difference in cycle time directly affects machine utilization and cost per part.
The timed test also tells you something about coolant management. If cut time per pass increases faster than expected as the tank fills with debris, your filtration is undersized for the material removal rate. Address it before production — don’t assume it will self-correct.
Where This Approach Has Limits
As-pressed ceramic cutting with an endless diamond wire saw handles this job well, but there are boundary conditions worth stating directly.
The contour cut on the large disk has a dimensional constraint. The SHI 100-R’s contour cutting capability is rated to Ø650mm. The large disk in this inquiry starts at 737mm and needs to reach 686mm — which is above that rated contour envelope. The cylinder at 355mm is well within range. For the disk, the OD trim step needs to be evaluated as a straight indexed cut approach rather than a full contour pass, or the job routes to a larger machine. This is something we work through with the customer on a case-by-case basis. It’s worth asking about before finalizing your cutting plan.
Green body parts are fragile under clamping. As-pressed blocks haven’t been through sintering densification. High clamping force on a localized contact area can cause surface indentation or edge damage before the wire ever touches the part. Use broad-contact fixtures — full-face backing plates, soft-faced clamps — and keep clamping force at the minimum needed for stability. We’ve seen as-pressed blocks marked by standard hard-jaw clamping even before the first cut.
Surface quality on as-pressed parts is good but not optical grade. The cut surface finish achievable on green body ceramics is suitable for downstream grinding or functional assembly use. It is not suitable for direct optical or precision sealing applications without additional surface preparation. If the customer’s end use requires Ra < 0.4μm directly off the wire, a sintered-state re-cut or lapping step will be needed.
Wire life estimation requires actual test data. The 3–5× throughput advantage over sintered material means wire consumption per block is lower — but we don’t have published wire life data specifically for this material formulation. Estimate wire life conservatively until you have 10–15 passes of real data from the timed test. Don’t schedule production wire orders based on comparable materials alone.
Practical Next Steps
If your process involves as-pressed ceramic cutting at similar block scale, here’s what to do in sequence:
Confirm the contour envelope first. Before anything else, verify that your largest workpiece OD after trim falls within the machine’s rated contour cutting diameter. For the SHI 100-R, that’s Ø650mm. Blocks larger than that need a different fixturing strategy for the OD trim step.
Build the timed test into your sample run. Don’t treat the efficiency benchmark as optional. The data from 5–8 consecutive timed passes on the half-round will tell you more about real-world throughput than any specification sheet. Log feed rate, elapsed time, and surface quality together — you need all three to make a production volume projection.
Start parameters conservatively and step up. Contour and bisect at 5 mm/min, straight slices at 10 mm/min. Confirm surface quality and dimensional check on the first two passes before increasing feed. As-pressed material tolerates more aggressive cutting than sintered, but it’s faster to step up from a working baseline than to diagnose problems after pushing too hard on the first pass.
Use white mineral oil and check the filter tank after each operation change. The debris character changes between contour passes and straight slices. Filter condition affects coolant performance and eventually cut quality. A 10-minute tank check between major operations is significantly cheaper than a degraded cut surface on the fifth disk slice.
For more real-world application data on découpe au fil de céramiques industrielles and large block processing, the Vimfun client case gallery has additional examples across ceramic, graphite, and composite materials.
Want the actual test results from this job? We ran the cuts. Contact us at levy@endlesswiresaw.com and ask for the as-pressed cutting test data — cycle times, surface quality measurements, and wire consumption per block. If you have a similar material and want to run your own test, we can set that up as well.
Technical references: ASTM C1161 — flexural strength testing of advanced ceramics at ambient temperature; ISO 14704 — fine ceramics, mechanical properties testing methodology.
