DJY Isostatic Graphite – QDZRT Graphite

Product Details

DJY Series comprises isostatic graphite grades manufactured by QDZRT Graphite. It is used when a project needs a comparatively uniform graphite structure, consistent machining behavior, and grade selection based on density, strength, electrical properties, purity, and component dimensions.

The table below does not convert representative typical source values into QDZRT Graphite guarantees. Numeric fields are published only after a stable QDZRT Graphite range or limit has been confirmed for that grade.

DJY Series Specification & Grade Architecture

Grade	Bulk Density(g/cm³)	Resistivity(μΩ·m)	Grain Size	Flexural Strength(MPa)	Compressive Strength(MPa)	Thermal Conductivity(W/(m·K))	CTE(×10⁻⁶/K)	Shore Hardness	Ash
DJY-T01	1.72 g/cm³	10–13 μΩ·m	—	30 MPa	65 MPa	100 W/(m·K)	5.0 ×10⁻⁶/K	40	500 ppm
DJY-T02	1.90 g/cm³	8–10 μΩ·m	—	55 MPa	105 MPa	135 W/(m·K)	3.6 ×10⁻⁶/K	55	500 ppm
DJY-T03	1.76 g/cm³	12–16 μΩ·m	8 μm	40 MPa	—	—	—	40	—
DJY-T04	1.88–1.92 g/cm³	10–14 μΩ·m	2 μm	60 MPa	125 MPa	110 W/(m·K)	3.9 ×10⁻⁶/K	75	—

Typical / reference properties unless a minimum or maximum value is explicitly stated. Final order specifications are confirmed by grade and batch.

Standard Isostatic Billet Dimensions & Sawn Blank Formats

QDZRT Graphite presses isostatic graphite using cold isostatic pressing (CIP) technology, ensuring identical compaction pressure from all directions. Standard billet geometries include:

Billet Format	Standard Dimensional Envelopes (mm)	Supply Options
Rectangular Billets (Blocks)	520 × 420 × 1200 mm 650 × 500 × 1850 mm 500 × 500 × 1000 mm	Full raw billet, pre-cut sawn blocks (-0/+2 mm), ground precision plates
Cylindrical Billets (Rounds)	Φ350 × 1800 mm Φ450 × 1200 mm Φ500 × 1200 mm Φ650 × 1000 mm	Full round logs, sliced discs, pre-turned cylindrical blanks, hollow rings
Custom Sawn Blanks	Cut precisely to customer bounding dimensions	Eliminates rough-machining waste, cuts shipping costs, and shortens customer cycle time

Ultra-Precision CNC Machining & Thin-Wall Feature Envelopes

Due to its micro-grain structure (2–15 μm) and isotropic mechanical strength, DJY Series isostatic graphite exhibits good edge retention under qualified CNC machining conditions. QDZRT Graphite provides drawing-based machining for high-specification applications:

Tight Machining Tolerances: Precision CNC contouring held to ±0.01 mm; standard dimensional features held to ±0.05 mm.
Micro-Rib & Fine-Detail EDM Features: High aspect-ratio thin ribs machined down to 0.2 mm wall thickness without corner chipping or burrs.
Superior Surface Finish: Surface roughness down to Ra ≤0.8 μm, ideal for optical glass hot-bending molds, semiconductor wafer carriers, and precision dies.
Cleaning & Assembly Inspection: Ultrasonic degreasing, cleanroom dust removal, CMM dimensional verification, and vacuum sealed nitrogen packaging.

Fine-grain isostatic graphite raw material and custom machined precision EDM electrode. — Comparison of DJY isostatic graphite raw stock and high-precision EDM electrode finish-machined to tight tolerances.

High-Purity Halogen Purification & Typical Applications

High-Purity Halogen Purification Options

For semiconductor, photovoltaic, and optical glass applications where metal impurities cause contamination or premature degradation, QDZRT Graphite provides high-temperature halogen gas purification:

Standard Industrial Grade: Ash content ≤0.1% (≤1000 ppm), suited for general EDM tooling and metallurgical casting.
High-Purity Purified Grade: Ash content ≤20 ppm, certified for solar thermal fields and high-temperature vacuum furnaces.
Ultra-Pure Electronic Grade: Ash content ≤5 ppm, specifically engineered for semiconductor crystal pulling, ion implantation, and epitaxial susceptors.

Typical Industrial Applications

EDM electrodes and precision molds for automotive, electronic, and aerospace tooling
Precision machined graphite plates, rings, fixtures, and drawing-based components
Vacuum furnace fixtures, heating elements, and critical hot-zone components
Semiconductor-related and photovoltaic graphite components where high purity and uniform thermal behavior are required
3D hot-bending molds for cover glass and precision optical lens pressing

Supply, Custom Machining & Grade Selection Guidance

Supply Formats & Machining Inquiries

DJY Series material can be discussed as raw blocks, cut blanks, or drawing-based machined components. Block dimensions, machining allowance, grain size, purification, and inspection requirements should be confirmed together rather than selected from density alone.

Engineering Grade Selection Criteria

Send the application, finished-part size, required density or strength, purity/ash limits, electrical or thermal requirements, and drawing if available. QDZRT Graphite will match the requirement to the appropriate DJY specification and confirm the available property combination before order.

Frequently Asked Questions (FAQ)

Q1: Why is isostatic graphite preferred over molded graphite for EDM electrodes?

Isostatic graphite features an ultra-fine grain size (2–15 μm) and isotropic microstructure, meaning its mechanical and electrical properties are identical in all directions. This allows intricate, thin-walled electrodes to be machined with sharp corners without edge chipping. During electrical discharge machining, it delivers lower electrode wear ratios, faster material removal rates, and superior workpiece surface finishes.

Q2: Which DJY grade is recommended for high-detail mold cavities?

For high-detail mold cavities, 3D glass bending, and thin-rib electrodes, DJY-T03 (Fine-Grain EDM) and DJY-T04 (Precision Mold / Ultra-Fine) are recommended due to their minimal particle size, high flexural strength, and superior edge retention.

Q3: What export compliance and testing documentation is provided with DJY graphite blocks?

Batch test documentation and any applicable export-control documents are confirmed by the selected grade, destination, end use, and order requirements before shipment.