TiSiN Coated Cutting Tool With High-Nitrogen Nanocrystalline Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional TiSiN coated cutting tools have low crystallinity and high amorphous phase content, leading to increased tool damage in severe environments, such as high-hardness steel processing, due to insufficient nitride formation and impurity presence.
Innovation Solution
A coated cutting tool with a hard nitride coating film composed of Ti and Si, optimized with a nitrogen content ratio of 50.0 at% or higher over the film thickness direction, a NaCl type crystal structure, and controlled crystal grain size of 5 nm to 30 nm, and reduced oxygen and carbon content, enhancing durability through improved residual compressive stress and crystallinity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional arc ion plating method is used to coat TiSiN, then coating process is simple and cost-effective, but nitrogen content ratio decreases and perfect nitride formation becomes difficult
Solution Approach 1:
The patent changes the coating method from conventional arc ion plating to sputtering method, and adjusts process parameters including using Ti-Si alloy target with specific composition (Ti:Si=95:5 to 98:2 atomic ratio), controlling substrate temperature at -20°C to +200°C, and adjusting sputtering power and gas flow rates to achieve nitrogen content ratio of 50 at% or higher throughout the film thickness
Solution Approach 2:
The patent introduces an intermediate layer between the substrate and the TiSiN coating layer. This intermediate layer serves as a buffer to improve adhesion and control the nitrogen diffusion, enabling better nitrogen content distribution throughout the coating thickness while maintaining coating quality
2Strength
If high silicon content is added to TiSiN coating, then wear resistance improves, but crystallinity decreases and amorphous phase increases
Solution Approach 1:
The patent optimizes the silicon content parameter within a specific range (2-18 atomic%) and controls the sputtering process parameters including substrate temperature, gas pressure, and power density to achieve the right balance between wear resistance and crystallinity, producing a coating with fine crystal grains (5-30 nm) and high nitrogen content
Solution Approach 2:
The patent creates a composite coating structure combining TiSiN with controlled crystal grain sizes and specific phase composition. The coating contains a mixture of crystalline phases with fine grain structure and controlled amorphous content, achieving both wear resistance and structural stability
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 optimized coating film structure significantly improves the durability of the cutting tool by increasing heat resistance and wear resistance, reducing tool damage, and maintaining tool performance in high-efficiency processing of high-hardness steels.
Implementation Method 1
a nitride mainly composed of Ti and Si coated by a sputtering method
Implementation Method 2
a nitride mainly composed of Ti and Si coated by a conventional arc ion plating method
Data Source
Figure 1~2
Figure 3
AI summary
The present invention discloses a coated cutting tool having a hard coating film on a surface of the tool. The hard coating film is a nitride, the content ratio of titanium (Ti) and silicon (Si) with respect to a total amount of metal elements (including semimetal elements) are in a range of 70 at% to 95 at% and 5 at% to 30 at% respectively. The content ratio of argon (Ar) with respect to the total amount of metal elements (including semimetal elements) and non-metal elements is 0.1 at% or less. The hard coating film has a NaCl type crystal structure and has an average crystal grain size in a range of 5 nm to 30 nm. With respect to a composition at every 20 nm of the hard coating film from a depth of 20 nm to 200 nm, the content ratio of nitrogen is 50.0 at% or higher in a case in which the total content ratio of metal elements (including semimetal elements), nitrogen, oxygen, and carbon is 100 at%.