Center Of Super-Diamond and Advanced Films (COSDAF)

Nanodiamond & Superhard Thin-films

Superhard Coatings and Processing Technologies for Advanced Manufacturing Devices

Funding Source and Organization

Innovation and Technology Fund, by the Innovation and Technology Commission of the Hong Kong

Principal Investigator

Dr. W.J. Zhang

Award

ITF Share: HK$899,500; Sponsorship Share: HK$100,000

Project Period

1/9/06 - 31/8/07

Based on close cooperation with industry, this proposal aims to develop new superhard film coated devices for applications in advanced manufacturing industry. Two distinctive materials, diamond and cubic boron nitride (cBN) (the hardest and the second hardest materials in the world with outstanding physical and chemical properties), and their combinations will be employed for the new products.

The project will focus on: (i) developing cBN and diamond based superhard coatings on tooling inserts by using physical and chemical vapor deposition (PVD and CVD) methods; (ii) constructing of diamond-cBN superlattices to further enhance the superhard coatings in tooling and tribological applications; and (iii) evaluating of the performance of superhard-film-coated tools in practical machining tests of hard alloys.

The team at City University of Hong Kong (CityU) has an outstanding track record in the field of superhard coatings, including diamond, cBN and diamond-like carbon (DLC) films, and is equipped with a comprehensive set of thin film deposition and characterization facilities. The proposed project will enhance the infrastructure and technology base in the manufacturing industry in Hong Kong.

Scope of the project

CityU will utilize the existing R&D facilities (including 3 microwave CVD deposition systems operating in both conventional and electron cyclotron resonance (ECR) modes, two magnetron sputtering systems, and comprehensive and advanced analytical and testing equipments) to develop new superhard coatings and processing technologies for advanced manufacturing devices. Two distinctive materials, diamond and cubic boron nitride (cBN) (the hardest and the second hardest materials), and their combinations will be employed for the new products. The implementation of the project will be based on close cooperation with industry, aiming to develop new-generation, high-performance manufacturing devices for practical applications. The proposed project has the following objectives:

To develop cBN and diamond based superhard coatings on manufacturing devices by using physical and chemical vapor deposition methods, for the improvement of stability, operation lifetime, efficiency and production yield of devices.
To construct diamond-cBN superlattices for further enhancement of the superhard coatings for cutting and tribological applications. The influence of layer number, layer thickness and crystalline nature on the adhesion and mechanical properties of the multilayer structures will be studied.
To evaluate the performance of superhard-film-coated tools in practical machining tests of a wide range of materials including ferrous materials and other hard alloys.

Because of the extreme properties of diamond and cBN, the synthesis and processing of these materials have been extremely difficult and challenging. We have developed several new techniques for the nucleation and growth of high-quality diamond and cBN films, and particularly advanced the cBN technology to the cutting edge of science and art. Our already well-established technology, outstanding track record and know-how in further progress will provide a solid background for achieving the objectives proposed in this project.