Thick Wall Industrial Use Jewelry Casting Aluminum Coated Graphite Crucible for Jewelry Foundry

Product Description

Product Description

In vacuum deposition processes, the performance of the evaporation source container directly determines the purity, uniformity, and deposition efficiency of the film. Conventional containers are prone to volatilization at high temperatures and react with molten metals, becoming sources of contamination. Ningheda's high-purity vacuum evaporation graphite crucibles are specifically designed to address this critical challenge. We utilize isostatic-pressed high-purity graphite substrates to control impurities at the source, ensuring exceptional stability even under extreme operating conditions. This provides a pure and reliable evaporation environment for your optical, semiconductor, and functional thin-film deposition applications.

Why Choose Ningheda Graphite Crucibles?

-Ultimate Purity Ensures Coating Quality: By using high-purity graphite raw materials (ash content ≤0.05%), we fundamentally eliminate the volatilization of impurities from the crucible itself at high temperatures. This effectively prevents defects such as pitting and pinholes during the coating process, ensuring high surface finish and superior performance for aluminum and other metal coatings.

-High-Density Matrix Resists Severe Corrosion: Through isostatic pressing, our graphite material achieves a high bulk density (≥1.90 g/cm³) and low porosity (≤11%). This dense, uniform microstructure maximizes resistance to penetration and erosion by molten aluminum and gaseous aluminum particles, significantly delaying the corrosion process of the crucible.

-Superior thermomechanical properties ensure process stability: The product combines excellent thermal shock resistance with high mechanical strength (compressive strength ≥70 MPa). Whether subjected to rapid heating and cooling cycles or mechanical stress during equipment operation, the crucible maintains stability, preventing cracking or breakage and ensuring the reliability of continuous production.

-Precision machining enhances operational efficiency: The crucibles feature high dimensional accuracy and smooth inner and outer surfaces. This not only facilitates installation and replacement but also reduces material residue on the walls, improving material utilization. Additionally, graphite's excellent thermal conductivity (resistivity ≤ 12 μΩ·m) ensures rapid and uniform heat transfer, shortening melting times and reducing energy consumption.

Specification

Performance Specifications	Parameter values	Key Role
Particle size	≤25mm	Optimize the density of the raw material to improve impact resistance
Bulk density	≥1.90g/cm³	Enhance resistance to molten aluminum erosion and penetration
Compressive strength	≥70MPa	Ensure structural stability in high-temperature environments and prevent deformation
Flexural strength	≥35MPa	To withstand rapid temperature changes and reduce the risk of cracking
Porosity	≤11%	Reduce molten aluminum penetration loss and extend service life
Resistivity	≤12μΩm	Improve heat transfer efficiency and reduce molten aluminum melting time
Ash content	≤0.05%	Prevent the volatilization of impurities and ensure coating purity
Shore hardness	60HSD	Improve surface wear resistance and reduce molten aluminum adhesion

Company Profile

Packaging & Shipping

Our graphite products are packed in professional export-grade plywood crates. Constructed from high-quality multi-layer boards and reinforced with green cross-strapping, the crates are sturdy and durable. Each crate bears detailed labels indicating product specifications, weight, and box number for efficient warehouse management and customs inspection. This packaging solution has been verified through multiple international long-distance shipments, ensuring products arrive at your facility in perfect condition.

Certifications

FAQ

Q1: Can this crucible be used for vacuum evaporation coating of other metals?

A: This product is specifically designed for aluminum evaporation. If you need to use it for coating other metals such as copper or silver, please contact us to order a custom-formulated graphite crucible to ensure compatibility and coating quality.

 

Q2: How can I tell if the crucible needs to be replaced?

A: Replacement is recommended under the following circumstances: visible corrosion or flaking on the inner walls of the crucible; deformation that exceeds the equipment's compatibility range; or frequent quality issues such as impurity spots or pinholes during the coating process.

 

Q3: How do I choose the right crucible size?

A: When selecting a crucible size, you should consider factors such as the type of material to be evaporated, the evaporation volume, and the size of the equipment chamber. You can refer to our product specifications sheet or contact our technical staff, and we will provide you with professional guidance on selecting the appropriate model.

 

Q4: What is the typical service life of a crucible?

A: Under standard vacuum aluminum sputtering processes, the service life is approximately 300–500 cycles, depending on the operating temperature, heating and cooling rates, and operating procedures. Proper use and maintenance can extend the service life.

 

Q5: What is the purity level of your graphite crucibles?

A: We use high-purity graphite raw materials with ash content controlled below 0.05%, ensuring extremely low contamination during the evaporation process.