新型超硬纳米复合材料英文文献和中文翻译

Development of Novel Coating Technology by Vacuum Arc with Rotating Cathodes for Industrial Production of nc-(Al1−xTix)N/a-Si3N4 Superhard Nanocomposite Coatings for Dry, Hard Machining 79602

The development of novel superhard nanocomposite, nano-layered coatings and of the coating technology based on vacuum arc evaporation from rotating elec- trodes is summarized。 The nc-(Al1−x Tix )N/a-Si3N4 coatings in which the nano-

crystals of the Al-rich solid solution with the fcc crystal structure of TiN are

imbedded into a thin matrix of amorphous silicon nitride show high thermal stability, oxidation resistance and excellent performance in dry, fast machining that is superior to the state-of-the-art (Ti1−x Alx )N coatings。

KEY WORDS: Superhard nanocomposites; industrial applications; (AlTi)N/Si3N4; Al–Ti–Si–N; vacuum arc。

1。INTRODUCTION

The demand for the improvement of machining technology in terms of higher cutting speed, better quality of the machined surface, lower con- sumption of lubricants and coolants calls for the development of new wear resistant coatings for machining tools。 Because the costs of environmen- tally friendly recycling and disposal of the coolants represent a signifi- cant part of the total machining costs, the ultimate goal is dry, high speed machining。 Under such conditions, the temperature of the cutting tool and of the coatings can reach 800◦C or more。 This poses strong requirements on the quality of the coatings, such as a high hardness combined with

1SHM Ltd。, CZ-78803 Novy Malin 266, Czech Republic。

2PLATIT AG, Moosstr。 68, CH-2540 Grenchen, Switzerland。

3Institute for Chemistry of Inorganic Materials, Technical University Munich, Lich- tenbergstr。 4, D-85747 Garching/Munich, Germany。

4To whom correspondence should be addressed。 Telephone: +49 89 289 136 24; fax: +49

89 289 136 26; e-mail: veprek@ch。tum。de

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a high resistance against crack formation and adherence to the substrate, high temperature stability and oxidation resistance, low coefﬁcient of fric- tion, absence of reaction with the material being machined and others。 For

(1, 2)

these reasons, the earlier developed (Ti1−x Alx )N coatings

and more

recent (Tix Aly Yz )N, (Tix Aly Yz Crc )N coatings with a high oxidation resis-

tance(3, 4) and similar coatings alloyed with Hf, Zr, V and other elements in order to improve the cutting performance are progressively replacing TiN。

Also superlattice coatings (“heterostructures”), that show enhanced hardness when the superlattice period decreases to 5–8 nm,(5, 6) are receiv- ing increasing attention as protection coatings of machining tools at industrial scale。(7) Much work is also devoted to the development of self-lubricant hard coatings, low friction coatings for bearings and others。(8)

In the present paper we shall concentrate on the recently devel- oped superhard nanocomposites that are formed according to the generic design principle(9, 10) by self-organization due to thermodynamically driven spinodal phase segregation。 It will be shown that the superhard nano- composites nc-(Al1−x Tix )N/a-Si3N4 with hardness of ≥40GPa posses a high thermal stability and meet the requirements for a new generation of

advanced wear resistant and tribological coatings。 In order to achieve the formation of the stable nanostructure during the deposition a new coating technology based on rotating vacuum arc cathode was developed。新型超硬纳米复合材料英文文献和中文翻译:http://www.youerw.com/fanyi/lunwen_92149.html