Hard and Superhard Nanomaterials

Instructor: Igor Konyashin

Course Summary

This course focuses on physicochemical fundamentals, technological aspects and applications of hard and superhard nanomaterials. The history of hard and superhard materials is briefly reviewed with an emphasis on historical aspects of cemented carbides, synthetic diamond and cubic boron nitride. Phase diagrams, compositions and properties of industrial cemented carbides as well as basic technologies for their fabrication are described. The structure of cemented carbides on the micro-, nano- and atomic-level is revealed. Industrial nanograined cemented carbides comprising either nanostructured binders or nanostructured carbide phases are considered. Wear damage, wear mechanisms and applications of conventional versus nanostructured cemented carbides are described. Physicochemical fundamentals and technological aspects of nanostructured ceramics and superhard materials are reviewed. Finally, modern trends in research and development on hard and superhard materials are addressed.

Course Format

Hours of lectureHours of discussionHours in laboratoryHours of independent studyTotal numbers of hours
20644878

Learning Outcomes

  • Demonstrate an understanding of physicochemical fundamentals of fabrication processes with respect to cemented carbides, ceramics and superhard materials;
  • Demonstrate an understanding of basic technologies for the manufacture of cemented carbides;
  • Demonstrate an awareness of wear damage, wear mechanisms and applications of conventional and nanostructured hard materials;
  • Demonstrate an appreciation of physicochemical fundamentals and technological aspects of nanostructured ceramics and superhard materials;
  • Demonstrate an awareness on up-to-date methods for the examination of hard and superhard nanomaterials;
  • Demonstrate an understanding of the structure of hard and superhard nanomaterials on the micro-, nano- and atomic-level;
  • Demonstrate knowledge of modern treads in research on hard and superhard materials.

Course Content

Part I. The history of hard and superhard materials (2 hours)

  • Introduction.
  • The history of cemented carbides: The discovery of WC-Co cemented carbides in Germany, the beginning of the industrial production of cemented carbides and their further development in the West, the history of cemented carbides in the Soviet Union.
  • The history of synthetic diamond: The discovery of the synthetic diamond technology at ultra-high pressures, the beginning of the industrial production of synthetic diamond and polycrystalline diamond (PCD), the history of diamond chemical vapour deposition (CVD).
  • The history of cubic boron nitride: The discovery of cubic boron nitride (c-BN), the beginning of the industrial production of c-BN and polycrystalline c-BN (PCBN) in the Western countries and Soviet Union.

Part II. Phase diagrams, compositions, structures and properties of cemented carbides as well as basic technologies for their fabrication (6 hours)

  • Phase diagrams and compositions of cemented carbides: the W-Co-C phase diagram, the W-Ti-(Ta)-Co-C phase diagram, typical industrial carbide grades for mining and construction, typical industrial carbide grades for wear parts, typical industrial carbide grades for metal-cutting.
  • Basic technologies for the fabrication of cemented carbides: the fabrication of WC and Co powders, milling, granulation, pressing, alternative moulding techniques, sintering, grinding, brazing.
  • Structure of cemented carbides: structure on the micro-level, structure of the nano-level, structure on the atomic-level.
  • Properties of cemented carbides: physical properties, corrosion behaviour, mechanical properties, performance properties.

Part III. Nanostructured cemented carbides (8 hours)

  • Cemented carbides with nanograin reinforced binders: the influence of carbide heat-treatments on the binder nano-structure, the structure of Co-based binders reinforced by nanograins, microstructure and properties of industrial cemented carbides with nanograin reinforced binder.
  • Cemented carbides with nanostructured carbide phase: nano and near-nano WC powders, industrial near-nano cemented carbides, perspective of cemented carbides comprising nanostructured WC grains.
  • Carbide hard-face materials with nanostructured binders: basic technologies for obtaining hard-face materials, the structure of Fe-based binders reinforced by nano-whiskers, the structure of the nanograined binder matrix, properties and applications of hard-facing with nanostructured binder.
  • Wear damage of conventional versus nanostructured cemented carbides: the ASTM wear tests, wear damage and wear mechanisms in the ASTM wear tests, wear damage and wear mechanisms in mining and construction applications, wear damage and wear mechanisms in metal-cutting.

Part IV. Nanostructured ceramic and superhard materials (2 hours)

  • Nanostructured ceramic materials: basic technologies, micro- and nano-structure, mechanical and performance properties, applications.
  • Nanostructured superhard materials: basic technologies for fabrication of nano-diamonds, micro- and nano-structure of nanostructured PCD and PCBN, nano-structured CVD diamond films, mechanical and performance properties, applications.

Part V. Modern trends in research on hard and superhard materials (2 hours)

  • Modern trends in research on cemented carbides: functionally graded cemented carbides, diamond-containing cemented carbides, Co-coated cemented carbides.
  • Modern trends in research on PCD and PCBN: functionally graded PCD, alternative substrates for PCD, superhard materials obtained at low pressures.

Reading List

Core Texts:

  1. Comprehensive Hard Materials, Elsevier Science and Technology, Editor-in-Chief V. Sarin, 2014.
  2. G. Kreimer. Strength of Hard Alloys, Consultants Bureau, NY, 1968.

Secondary Text:

  1. P. Schwarzkopf and R. Kieffer, Refractory Hard Metals, The Macmillan Company, 1968.

Peripheral Reading:

  1. G.S. Upadhyaya, Nature and Properties of Refractory Carbides, Nova Science Publishers, Inc., 1996.

Grading

Class participation20%
Homework assignments30%
Final exam50%