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Carbide and nitride nanocomposite coatings: development and application of analytic bond-order potentials

碳化物和氮化物纳米复合涂层：解析键序势的开发和应用

基本信息

批准号：
EP/E065902/1
负责人：
David Pettifor
金额：
$ 58.88万
依托单位：
University of Oxford
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2008
资助国家：
英国
起止时间：
2008 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FE065902%2F1
关键词：
Carbide nitride nanocomposite coatings development

项目摘要

The goal of this project is to combine the expertise of two scientific groups in the United Kingdom and Germany in order to advance the fundamental understanding of nanocomposite hard coatings at the atomic scale.In industry, carbide and nitride compounds are widely used as coatings of metal-shaping tools for cutting, milling, lathing, or wire-drawing. These coatings have polycrystalline structures on the micrometer scale (where one micrometer corresponds to one in a thousand parts of a millimeter). They must be sufficiently hard, tough, heat and wear resistant for economical and reliable use in industrial production.Recently, materials research has been focusing on the improvement of the functional performance of these materials by structuring them on a scale that is a thousand times finer than before. Superhard or supertough nanocomposites are composed of nanometer-sized crystalline grains (where one nanometer is one in a thousand parts of a micrometer) seperated by an amorphous phase.Hitherto, most of the technological achievements for nanocomposites have been obtained through experimental research and a large amount of trial and error. The scientific understanding of microscopic mechanisms and processes, which relate the microscopic structural properties of interfaces to the macroscopic mechanical properties, is still mostly empirical and not yet very detailed. However, this understanding is an important prerequisite for the control and optimisation of the synthesis of nanocomposite materials for improved performance. Nowadays, atomistic computer simulations have become well recognised in materials science and technology as valuable and predictive means which augment experimental characterisation and analysis.The atomistic computer simulations require a knowledge of the forces which act between the atoms in the coatings. Whereas these interatomic forces are well-known for ionic systems such as rock salt, they are less well characterized for covalent carbide and nitride systems thatcomprise the cyrstalline and amorphous phases of coatings.The Oxford-based proposal will develop a novel class of interatomic potentials, the so-called bond-order potentials (BOPs), which will be capable of describing and analysing the structures and properties of nanocomposites. We will parameterize the BOPs using a database of veryaccurate but computationally very demanding reference calculations for a wide range of different crystal structures. With the potentials developed at Oxford, atomistic simulations of nanocomposites will then be carried out in close collaboration with IWM and compared to experimental work.

该项目的目标是结合英国和德国两个科学小组的专业知识，以促进在原子尺度上对纳米复合硬质涂层的基本了解。在工业上，碳化物和氮化物化合物被广泛用作金属成形工具的涂层，用于切割、铣削、车削或拉丝。这些涂层在微米尺度上具有多晶结构(一微米相当于千分之一毫米)。它们必须具有足够的硬度、韧性、耐热性和耐磨性，才能在工业生产中经济可靠地使用。最近，材料研究的重点是通过在比以前精细一千倍的尺度上构造这些材料来提高其功能性能。超硬或超韧纳米复合材料是由纳米晶(一纳米是千分之一微米)由非晶相隔开组成的，目前纳米复合材料的大部分技术成果都是通过实验研究和大量的试错而获得的。对微观机制和过程的科学理解，将界面的微观结构属性与宏观力学属性联系在一起，仍然主要是经验的，还不是非常详细。然而，这一理解是控制和优化纳米复合材料合成以提高性能的重要前提。如今，原子计算机模拟在材料科学和技术中已被公认为是一种有价值的和可预测的手段，可以增强实验表征和分析。原子计算机模拟需要了解涂层中原子之间的作用力。虽然这些原子间作用力在岩盐等离子体系中是众所周知的，但对于包括涂层的晶相和非晶相的共价碳化物和氮化物体系来说，它们的特征就不那么好了。牛津大学的这项提议将开发一类新的原子间作用力，即所谓的键序势(BOPS)，它将能够描述和分析纳米复合材料的结构和性能。我们将使用一个非常精确但计算要求非常高的数据库，对各种不同的晶体结构进行参考计算，对BOPS进行参数化。随着牛津大学开发的潜力，纳米复合材料的原子模拟将与IWM密切合作进行，并与实验工作进行比较。