Quick Answer: Sintering Makes the Segment; Welding or Brazing Attaches It
A diamond core bit has two separate manufacturing decisions. Hot pressing and sintering make the metal-bond diamond segment. After that segment is finished, a separate process joins it to the steel tube.
The three buyer-facing joint labels in this guide are laser-welded joint, high-frequency brazed joint and silver-brazed joint. Laser welding is a fusion process without a separate low-melting filler layer. High-frequency brazing describes induction heating. Silver brazing describes an Ag-bearing filler system. Because induction can heat a silver-brazed joint, the last two labels can overlap; procurement documents should name both the heating method and filler alloy.
Segment Manufacturing and Attachment Are Two Independent Axes
| Decision | What it controls | Typical specification |
|---|---|---|
| Inside the segment | Diamond position, matrix density, retention and wear | Random, uniform or ARIX ordered placement; hot-pressed sintered metal bond |
| Segment to tube | Joint strength, heat tolerance and failure mode | Laser welded; high-frequency induction brazed; silver brazed |
This removes the common catalogue error of showing “sintered” beside laser welding and brazing as if all three were attachment methods. A segment can be hot-pressed and sintered internally, then laser welded or brazed to the tube.
How the ARIX Segment Is Made
- Layer preparation: metal-bond powder is metered into thin layers.
- Ordered placement: diamond crystals are positioned at controlled spacing between those layers, creating the ARIX three-dimensional cutting pattern.
- Pressing and sintering: the layered compact is densified under heat and pressure. The matrix bonds around the diamonds and locks the pattern through the usable segment depth.
- Joining foot: a diamond-free transition base can be engineered at the bottom of the segment to give the laser a stable metal zone.
- Finishing: the segment is sized, exposed and prepared for positioning on the core tube.
Sintering is powder metallurgy, not casting. The matrix is consolidated and metallurgically bonded around the diamonds; the manufacturing target is controlled density, retention and wear—not simply melting all powders into a liquid block.
Three Segment-to-Tube Joint Labels
Laser-welded joint: the laser fuses a diamond-free transition foot on the segment to the steel tube without a separate low-melting filler layer. It is the preferred direction for reinforced concrete, dry cutting and high thermal-mechanical load, provided weld depth, positioning and destructive sample tests are controlled.
High-frequency brazed joint: an induction coil heats the joint rapidly and locally while capillary action draws the approved filler through the clearance. The process can be fast and repeatable for production, but “high frequency” alone does not identify the filler chemistry.
Silver-brazed joint: an Ag-bearing filler joins the finished segment to the tube. Heating may come from high-frequency induction or a controlled flame, so silver brazing is not automatically a separate category from high-frequency brazing. It is widely used for wet coring and large-diameter programs where joint temperature remains inside the approved process window.
For RFQs, ask for the heating method, filler alloy, joint clearance, temperature window, fillet inspection and sample acceptance. Do not accept “brazed” as the complete joint specification.
Why Vacuum Brazing Is a Different Route
Vacuum-brazed tools normally start with a shaped steel body, active braze alloy and loose diamond grit. During the furnace cycle, active elements react at the diamond-alloy interface and retain a highly exposed, single cutting layer. The open grit cuts aggressively and handles mixed materials well.
The trade-off is diamond reserve. An impregnated sintered segment reveals additional diamond as the matrix wears; a conventional monolayer vacuum-brazed tool finishes when its exposed layer is consumed. This is why vacuum-brazed rescue blades, pipe blades and specialty hole saws sit on a different product architecture from deep reinforced-concrete ARIX core bits.
ARIX, Heavy Rebar and Glazing
Hard aggregate and heavy rebar do not glaze a segment in the same way. Mineral aggregate fractures into abrasive particles; steel reinforcement is ductile, heat-generating and prone to producing adhesive swarf at the cutting face.
A very soft bond can release active diamonds before they finish cutting the bar. A very hard bond can retain flattened diamonds and let the face polish. ARIX attacks this problem through geometry: regular diamond spacing reduces clusters and diamond-free zones, distributes reaction force across more active cutting points and maintains a repeatable exposure pattern through successive layers.
The ordered gaps also create regular chip-clearance and coolant paths at the cutting face. The commercial result is higher utilization of active diamonds, smoother load on the rig and more consistent progress through concrete-to-rebar transitions. ARIX does not remove the need for the correct bond and water flow; it gives the engineer a more controllable cutting structure.
Grit, Concentration, Bond and Cooling
| Variable | Heavy-rebar direction | Why it matters |
|---|---|---|
| Grit | Medium to coarse starting range | Higher protrusion and stronger individual cutting points |
| Concentration | Medium to medium-high, layout controlled | Effective spacing matters more than maximum loading |
| Bond | Retention-led with controlled self-sharpening | Balances pull-out resistance against removal of flattened diamonds |
| Cooling | Stable water flow and slurry evacuation | Controls heat and clears iron-rich swarf from the face |
OEM RFQ Specification
Diamond core bit Ø132 mm × 450 mm for wet drilling in reinforced concrete. Segment: hot-pressed sintered metal bond with ARIX ordered diamond placement; grit, concentration and bond matched to aggregate and rebar density. Segment-to-tube joint: laser welded, or approved high-frequency induction-brazed / silver-brazed construction for the stated wet duty. Confirm heating method, filler alloy where applicable, joint dimensions, tube thread, waterway, approved RPM and sample acceptance before production.
This wording keeps segment manufacture and attachment separate. Send Zhonghuan the rig power, diameter, concrete class, aggregate, rebar density, drilling depth and cooling condition; we return the segment architecture, joint route and sample plan as one production-ready specification.
Build an ARIX Core Bit Program
Send the machine, diameter range, aggregate and rebar condition. Zhonghuan matches ARIX placement, grit, concentration, bond, segment geometry and laser-welded joint in one production-ready RFQ.
Request ARIX Core Bit Specification
