Polycrystalline Diamond-like Carbon

What is Polycrystalline Diamond-like Carbon?

 

Polycrystalline diamond-like materials (or PCD-like materials) refer to carbon-based structures that mimic some key properties of polycrystalline diamond (PCD) but differ in composition, bonding, or synthesis methods. They typically exhibit high hardness, wear resistance, and thermal stability, though their performance may not fully match that of traditional PCD.

 

 

Polycrystalline like diamond refers to the use of polycrystalline diamond as raw material, which undergoes surface etching treatment to form a honeycomb pore structure, thereby achieving a grinding and polishing effect similar to polycrystalline diamond. Therefore, it is called "polycrystalline like" diamond. Polycrystalline diamond micro powder is a new type of abrasive between single crystal diamond and polycrystalline diamond. Made from polycrystalline diamond micro powder processed using special techniques.

 

Key Types

Binderless Polycrystalline Diamond

• Produced via chemical vapor deposition (CVD), consisting of pure diamond grains bonded without metal binders (e.g., cobalt).
• Advantage: Higher thermal stability (no binder degradation) and chemical purity.

Diamond-Like Carbon (DLC) Aggregates

• Composed of nanocrystalline diamond or sp³/sp² hybrid carbon phases with disordered polycrystalline structures.
• Features: Lower hardness than PCD but offers low friction, corrosion resistance, and tunable optical/electrical properties.

 

 

Characteristics

Structure: Nano/micro-scale diamond crystallites (or DLC phases) in a disordered matrix.

Properties:

• High wear resistance (though often inferior to PCD).
• Moderate thermal conductivity (lower than single-crystal diamond).
• Potential for smooth surfaces and biocompatibility (DLC-based variants).

Synthesis:

• CVD/PVD: For thin films or coatings.
• HPHT (rare): Modified processes for binder-free PCD analogs.

 

Characteristics and Applications:

• It has the characteristics of moderate hardness, strong grip, strong self sharpening, high grinding efficiency, and can significantly reduce the surface roughness of workpieces. It is used for precision grinding and polishing in fields such as silicon carbide, sapphire substrate chips, optical lenses, ceramics, and alloys. It is an economical alternative product to polycrystalline diamond.

 

 

Applications

• Tool Coatings: Alternative to PCD for cost-sensitive or precision machining.
• Optics: Infrared windows or protective layers due to transparency and durability.
• Biomedical: Coatings for implants (e.g., joint replacements).
• Electronics: Heat spreaders or insulating layers (requires optimized thermal properties).