Pyrolytic Boron Nitride Tube
Edgetech Industries, Advanced Ceramics Division supplies Pyrolytic Boron Nitride (PBN) Tube with high-quality and competitive prices.
View productCrucible Performance and Selection Guide
Crucible Performance and Selection Guide
Choosing a silicon nitride crucible starts with how it behaves in service. This guide reads the published data for the silicon nitride ceramic body the way a process engineer would — melt wetting first, then thermal shock, then chemical attack — and shows where the material is the right answer and where the published data stops.
Non-Wetting Surfaces Keep the Melt Where It Belongs
The product page describes a non-wetting surface and names the molten metals and alloys the crucible handles. For a buyer that means two practical things: the charge releases instead of clinging to the wall, and the crucible contributes almost nothing to the melt.
| Melt or alloy group | Named on the product page |
|---|---|
| Low-melt and soft metals | Zinc, cadmium, indium, lead, bismuth, gallium |
| Precious metals | Gold, silver |
| Structural light metal | Aluminium |
| Specialty melts | Germanium |
| Copper-base alloy | Brass (yellow copper) |
| Aluminium-base alloy | Duralumin (hard aluminium) |
| Nickel-base alloy | Nickel silver |
| Non-ferrous melting, general | Aluminium, copper and zinc and their alloys, named again in the page’s industrial metal-processing application |
Why the surface does not wet
The page credits the silicon nitride surface itself for the non-wetting behaviour and does not describe any coating step, so the property belongs to the ceramic body you receive rather than to a treatment that can wear off. The page also states minimal contamination risk for pure melts and a longer service life than alumina or zirconia crucibles — useful when a single contaminated heat costs more than the crucible.
Buyer decision
If your melt appears in the table above, non-wetting behaviour is a published feature and you can specify it with confidence. If your melt does not appear, treat wetting as unverified and ask the supplier before you commit a production heat to it.
Thermal Shock: What the Numbers Actually Buy You
Silicon nitride earns its place in cycling equipment because low expansion and shock tolerance work together. Low expansion means a given temperature step builds less internal strain; the published ΔT figure describes how large a step the material is rated to take.
ΔT 500 °C Thermal shock stability The published stability figure for rapid temperature change.
>3.1 × 10−6 K−1 Expansion, 20–1000 °C Low expansion is what keeps heat-up and cool-down stress manageable.
1200 °C Max operating temperature in air An oxidation limit rather than a mechanical strength ceiling.
The 1200 °C figure is often read as a strength limit. It is not. The page frames high-temperature capability around oxidation resistance and structural integrity in oxidising atmospheres, so the number describes how long the material resists oxidation in air — not the point at which it stops carrying load. Thermal conductivity of 15–20 W/(m·K) supports even heat distribution across the wall, which is the second half of the shock story.
Settle these four points before the first ramp-up
- Your largest single step change, checked against the ΔT 500 °C stability figure.
- The actual furnace atmosphere, checked against the in-air condition attached to the 1200 °C limit.
- Expected cycles per day and total cycle count, since the page notes that exact properties vary with the manufacturing method.
- Whether the part will be preheated before charging, and by what method.
Buyer decision
For batch furnaces and rapid-cycle work, specify against ΔT 500 °C and the expansion figure. For continuous duty at or above 1200 °C, specify against the atmosphere instead — that is the variable the page’s own data leaves open.
Chemical Resistance: The Envelope and Where It Stops
Chemical resistance is where data sheets get over-read. The product page names a specific set of aggressive media. Anything outside that list is unverified — not automatically unsuitable, but not something you should assume.
Inside the published envelope
- Boiling hydrochloric acid
- Concentrated nitric acid
- Aqua regia
- Sulfuric acid
- Aluminium hydroxide solutions below 25% concentration
- Weak alkaline corrosion
Outside the published envelope
- Strong or concentrated alkali — the page claims resistance to weak alkaline attack only
- Aluminium hydroxide solutions at 25% concentration and above, which fall outside the stated limit
- Hydrofluoric acid, which the page does not name at all
- Any medium you cannot find listed — ask before you run it
Tied to a manufacturing route
The page credits advanced gas pressure sintering with delivering durability in corrosive environments. That matters when you compare suppliers: the corrosion claim belongs to the sintered body produced that way, not to silicon nitride as a generic material name.
Buyer decision
For acid digestion and reaction-vessel work, quote the exact acid, its concentration and its boiling point in your enquiry. If your process uses alkali, hydrofluoric acid or a mixed bath, say so up front — that is the point where a different ceramic may be the better purchase.
Published Specification Table
The complete data set as printed for silicon nitride, including the two footnotes the supplier attaches to it.
| Property | Si3N4 value |
|---|---|
| Physical | |
| Colour | Gray black |
| Density | >3.2 g/cm³ |
| Mechanical | |
| Rockwell hardness | HRA 90 |
| Vickers hardness (Hv50) | >1550 HV0.5 |
| Elastic modulus at 20 °C | 290 GPa |
| Bending strength at 20 °C | >600 MPa |
| Compressive strength at 20 °C | 2500 MPa |
| Fracture toughness at 20 °C | >6.0 MPa·m1/2 |
| Thermal | |
| Thermal conductivity | 15–20 W/(m·K) |
| Coefficient of thermal expansion, 20–1000 °C | >3.1 × 10−6 K−1 |
| Thermal shock stability | ΔT 500 °C |
| Specific heat capacity | 700 kJ/kg·K (as printed) |
| Maximum operating temperature in air | 1200 °C |
| Electrical | |
| Dielectric strength (insulation strength) | 1 kV/mm |
| Volume resistance at 20 °C | 1012 Ω·cm |
* Tests under room temperature environment.
* The above information is offered for comparison only. Exact properties will vary depending on the manufacturing method.
Match Your Process to the Spec That Decides It
Six common buying situations, the single published figure that governs each one, and the question to settle before you place an order.
| Your situation | Spec that decides it | Confirm before ordering |
|---|---|---|
| Melting aluminium, zinc or copper alloys in a foundry | Non-wetting surface and the named metal list | Melt temperature, how dross is skimmed, and how the crucible is heated |
| Laboratory acid digestion or sample preparation | Acid envelope: HCl, HNO3, aqua regia, H2SO4, aluminium hydroxide below 25% | Acid type, concentration, boil duration, and whether any HF enters the bath |
| Batch or rapid-cycle furnace with fast ramps | ΔT 500 °C shock stability and expansion above 3.1 × 10−6 K−1 | Largest single step change, cycles per day, and the heating method |
| Continuous duty at or above 1200 °C | Maximum operating temperature in air: 1200 °C | Atmosphere and duty cycle — the page’s furnace-component section mentions continuous 1200 °C+ operations while the table sets 1200 °C in air |
| Glass melting or special alloy production components | High-temperature furnace component application | Which material the part contacts, and whether it is structural or a liner |
| Busy plant with manual handling and charging | Fracture toughness >6.0 MPa·m1/2 and HRA 90 hardness | Handling method and impact risk during charging and cleaning |
What Ships, and How It Is Made
A specification table tells you what the material can do. These four details tell you what arrives and how to describe the part you need.
Variants
SKU SiN-C covers two shapes on the product page: Silicon Nitride Crucible 1 and Silicon Nitride Tapered Crucible 2. Check the product page for which variant fits your furnace furniture.
Manufacturing route
Advanced gas pressure sintering — the process the page credits for durability in corrosive environments and for the wear and fracture behaviour quoted in the table.
Packing
Crucibles are handled to minimise damage during storage and transport, packed with suitable outer boxes and inner cushioning, with vacuum packing used for some parts.
Data caveat
Published properties are offered for comparison and vary with manufacturing method — so quote the same process data when you request a part.
Send Your Process Conditions, Not Just a Part Number
The product page has no online checkout — the stated route is to contact the supplier to select the right silicon nitride solution for your application. An enquiry that carries your process conditions gets a useful answer in one round instead of three.
- The metal, alloy or chemical the crucible will contact
- Maximum operating temperature and furnace atmosphere
- Heat-up and cool-down method, plus cycles per day
- Required geometry and dimensions, with a drawing if available
- Quantity per order and expected annual usage
- Delivery location and required date
Include the SKU SiN-C and the variant you are considering — Silicon Nitride Crucible 1 or Silicon Nitride Tapered Crucible 2 — so the reply can be specific.
Frequently Asked Questions
What information is shown for this product?
Review the product details, images, and specifications presented on the official product page.
Where can I check the intended application?
Use the application and use-case information published on the official product page.
Which specifications should I confirm before ordering?
Confirm the specifications and options listed for the exact product variant before placing an order.
Where can I check available options?
Check the official product page or ask the supplier about options shown for the selected product.
How can I request product information?
Use the official contact or inquiry path provided on the site.
What should I include in an inquiry?
Include the product page, intended use, required quantity, and any specifications you need the supplier to review.