DLC Composite Layers with Metal Nitride Buffer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diamond like carbon (DLC) thin films face issues with high residual stress and poor adhesion to substrates due to differences in lattice constants and thermal expansion coefficients, leading to fragmentation and reduced mechanical performance.
Innovation Solution
A composite material structure comprising a metal layer, a metal nitride layer, and a DLC thin film with a high sp3 diamond structure, where the metal layer includes aluminum, copper, zirconium, or vanadium, and the metal nitride layer includes their respective nitrides, is used, with physical vapor deposition to create a well-matched lattice constant interface, enhancing adhesion and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the ratio of sp3 diamond structure in DLC thin film is increased to improve hardness and mechanical properties, then the internal stress of the film increases, causing fragmentation and poor adhesion
Solution Approach 1:
The patent introduces an intermediate layer composed of metal (Al, Cu, Zr, or V) and its nitride between the substrate and the DLC thin film. This intermediate layer acts as a mediator that buffers the stress transmission and improves adhesion, allowing the DLC film to achieve high sp3 ratio (≥30%) without fragmentation. The intermediate layer's lattice constant is specifically selected to match well with both the substrate and the DLC film, reducing interface stress.
2Strength
If the ratio of sp3 diamond structure in DLC thin film is increased to improve mechanical performance, then the internal stress increases leading to film fragmentation
Solution Approach 1:
The intermediate layer of metal and metal nitride serves as a stress buffer that prevents film fragmentation. By selecting metals with appropriate lattice constants (Al, Cu, Zr, or V), the intermediate layer accommodates the high internal stress generated by high sp3 ratio DLC films, maintaining film integrity while achieving superior mechanical performance.
Solution Approach 2:
The patent creates a composite structure consisting of substrate + intermediate layer (metal + metal nitride) + DLC thin film. This composite material system combines the advantages of each layer: the substrate provides mechanical support, the intermediate layer provides stress buffering and adhesion enhancement, and the DLC film provides high hardness and wear resistance.
3Reliability
If an intermediate interface layer is added to reduce internal stress and improve adhesion, then the structural strength and adhesion are improved, but the device complexity increases
Solution Approach 1:
The intermediate layer uses a simple binary system of metal and its nitride, which can be deposited using conventional sputtering techniques. Although it adds a layer, the materials and processes remain relatively simple, with the metal layer being deposited first followed by its nitride formation or co-deposition, maintaining ease of manufacture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly improves the adhesion and mechanical strength of DLC composite layers, achieving a high sp3 diamond structure with enhanced hardness and durability, suitable for applications in mechanical, chemical, electrical, photoelectric, and heat transfer fields.
Implementation Method 1
physical vapor deposition to create a well-matched lattice constant interface
Implementation Method 2
during film coating, the surface of the film layer is bombed by coating particles continuously
Data Source
AI summary
A structural material of diamond like carbon (DLC) composite layers is provided. The structural material includes a composite material which is consisted of a metal layer, a first metal nitride layer, and a DLC thin film. The metal layer includes aluminum (Al), copper (Cu), zirconium (Zr), nickel (Ni), or vanadium (V). The first metal nitride layer includes aluminum nitride (Al—N), zirconium nitride (Zr—N), vanadium nitride (V—N), or nickel nitride (Ni—N). The DLC thin film of the structural material of DLC composite layers has high quality tetragonally bonded amorphous carbon (ta-C) with a sp3(C—C) bonding ratio of more than 30%. Therefore, it is suitable for the work pieces in the mechanical, chemical, electricity, photoelectric, and heat transfer fields.