STTR Phase I: Nano-Layered Composites as High-Temperature Hard Coatings

STTR 第一阶段：纳米层状复合材料作为高温硬质涂层

• 批准号: 9903698
• 负责人: Ilwon Kim
• 金额: $ 10万
• 依托单位: APPLIED THIN FILMS INC
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9903698&HistoricalAwards=false
• 关键词: STTR; Phase; Nano; Layered; Composites

This Phase I SmallBusiness Technology Transfer (STTR) project aims to investigate high-temperature properties of nano-layered coatings. A specific material system is chosen that optimizes key properties including hardness, thermal expansion match with cemented-carbide tools, stability against dissolution into steel workpieces, and oxidation resistance. The strong dislocation confinement in nano-layers will lead to better high-temperature hardness retention than in monolithic coatings. The oxidation resistance of the coatings will be evaluated. The stability of the nano-layered coatings will be investigated through annealing experiments with subsequent characterization by x-ray diffraction. There is a high level of interest in cutting-tool coatings that perform well over a range of temperatures (RT to 1100 C) because of the desire to cut at higher rates and increasing environmental concerns over the use of coolants during machining. However, traditional coating materials do not perform well, primarily because their hardnesses decrease rapidly as temperature rises. The proposer has recently developed a new class of coatings, combining many alternating nanometer-scale layers of BCC metals and rocksalt-structure nitrides, e.g. Mo/NbN. Results show that nano-layering provides substantial hardness enhancements. Hardnesses 30 GPa are maintained at high temperatures providing an opportunity to explore new high-temperature stable coatings. Nano-layer-coated cutting tools have the potential to make dry cutting a practical alternative to traditional wet cutting methods. In addition, they can improve we-machining economics by allowing higher cutting speeds.

这个第一阶段的小企业技术转让（STTR）项目旨在研究纳米层状涂层的高温性能。 选择特定的材料系统，优化关键性能，包括硬度、与硬质合金刀具匹配的热膨胀、防止溶解到钢工件中的稳定性以及抗氧化性。 纳米层中的强位错约束将导致比整体涂层更好的高温硬度保持率。 将评价涂层的抗氧化性。 纳米层状涂层的稳定性将通过退火实验与随后的X射线衍射表征进行研究。 人们对在一定温度范围内（RT至1100 ℃）表现良好的切削刀具涂层非常感兴趣，因为人们希望以更高的速度切削，并且在加工过程中使用冷却剂会增加对环境的关注。然而，传统的涂层材料表现不佳，主要是因为它们的硬度随着温度的升高而迅速下降。 提议者最近开发了一类新的涂层，结合了许多交替的BCC金属和岩盐结构氮化物（例如Mo/NbN）的纳米级层。 结果表明，纳米分层提供了显着的硬度增强。硬度在高温下保持在30 GPa，为探索新的高温稳定涂层提供了机会。 纳米涂层刀具有可能使干切削成为传统湿切削方法的一种实用替代方法。 此外，它们还可以通过允许更高的切削速度来提高切削加工的经济性。