PVD Multi-Layer Coating for Press Mold Wear Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High tensile steel sheets require higher pressing forces during press working, leading to increased mold abrasion and reduced mold lifetime, with existing hard coating films like TiC and TiCN having issues with adherence and slidability when formed by PVD methods, and CVD methods causing thermal deformation.
Innovation Solution
A pressing mold with a coating film composed of a TiN layer, a Ti(CxNy) layer with gradually increasing carbon concentration, and a TiC layer formed by the PVD method, providing high hardness, adherence, and slidability, and eliminating the need for dimension correction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CVD method is used to form TiC coating film, then adherence is improved, but thermal deformation occurs causing dimension correction requirement
Solution Approach 1:
The patent changes the processing temperature parameter from CVD conditions (1000°C or higher) to PVD conditions (below 500°C), thereby avoiding thermal deformation while forming the TiC coating film. This parameter change resolves the contradiction by selecting a deposition method that operates at lower temperatures, preventing mold body distortion while still achieving adequate coating adherence.
Solution Approach 2:
The patent introduces an intermediate TiCN coating layer between the TiC coating layer and the mold body. This intermediate layer acts as a mediator that improves the adherence of the TiC coating to the mold body when formed by PVD method, while the low temperature process prevents thermal deformation. The TiCN layer serves as a transitional interface that bridges the mold body and the TiC coating.
2Manufacturing precision
If PVD method is used to form TiC coating film, then thermal deformation is reduced, but adherence deteriorates
Solution Approach 1:
The patent creates a composite coating structure consisting of multiple layers: TiN layer, TiCN layer, and TiC layer. Each layer has different properties that complement each other - TiN provides strong adhesion to the substrate, TiCN provides transition and enhanced adhesion, and TiC provides the hard wear-resistant surface. This composite structure resolves the contradiction by combining materials with different functions to achieve both good adherence and low thermal deformation.
Solution Approach 2:
The patent segments the single-layer TiC coating into multiple functional layers (TiN, TiCN, TiC) deposited by PVD method. Each segment performs a specific function: TiN for substrate adhesion, TiCN for transition and adhesion enhancement, and TiC for wear resistance. This segmentation allows each layer to be optimized for its specific purpose while maintaining overall coating integrity and adherence.
3Reliability
If TiCN coating film is used, then adherence is improved, but slidability deteriorates due to low slidability
Solution Approach 1:
The patent adds a dimensional aspect by creating a multi-layer structure with vertical stratification. Instead of using a single material that compromises between adherence and slidability, the solution stacks multiple materials in layers, where TiCN provides adherence in the lower layers and TiC provides slidability in the upper layer. This vertical dimensionality allows both properties to coexist in different spatial zones of the coating.
Solution Approach 2:
The patent applies local quality by giving different regions of the coating different properties. The TiN and TiCN layers near the substrate provide strong adhesion, while the outer TiC layer provides high slidability and wear resistance. Each layer is locally optimized for its specific function, resolving the contradiction between adherence and slidability through spatial differentiation of material properties.
4Force
If higher pressing force is applied for high tensile steel sheet, then press working capability is improved, but mold abrasion increases
Solution Approach 1:
The patent uses a composite coating structure with TiN, TiCN, and TiC layers that work together to provide both the strength needed for high pressing forces and the wear resistance needed for extended mold lifetime. The combination of materials creates a coating that is both strong and abrasion-resistant, resolving the contradiction between handling high-strength materials and maintaining mold durability.
Solution Approach 2:
The patent changes the surface hardness parameter of the mold by applying a multi-layer coating with varying hardness properties. The TiC outer layer provides extreme hardness for wear resistance against high pressing forces, while the underlying TiN and TiCN layers provide toughness and adhesion. This parameter change in surface properties allows the mold to withstand higher pressing forces without proportional increase in abrasion.
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 coating film achieves high durability and bead drawing characteristics, reducing mold wear and production costs while maintaining excellent performance in press working of high tensile steel sheets.
Implementation Method 1
The coating film is formed by Physical Vapor Deposition method, and includes: a TiN layer formed on a surface of the mold body; a Ti(CxNy) layer formed on a surface of the TiN layer
Data Source
AI summary
A pressing mold for use in press working of a material includes a mold body, a coating film formed on the portion of the pressing mold that comes into contact with the material in the press working, the coating film being formed by PVD method. The coating film includes a TiN layer formed on a surface of the mold body, a Ti(CxNy) layer (wherein, x+y=1, x<1, and x gradually increases to 1 as it becomes more distant from the surface of the TiN layer) formed on the TiN layer, and a TiC layer formed on the Ti(CxNy) layer.