Preparation of Si-C-N nano-composite superhard thin film

Abstract

The present invention discloses a preparation process of superhard nanocomposite films of nanocrystalline h-Si3N4 / amorphous SiCN by industrial pulsed direct current plasma enhanced chemical vapour deposition device. In the detailed process, high-speed steel with hardness of HRC=60 is quenched at 1170DEG C, tempered at 550DEG C, then its surface is degreased, polished, cleaned with ultrasonic in acetone and dehydrated with ethanol. After that it is moved into the industrial pulsed direct current PCVD vacuum furnace as the substrate material for the preparation of the superhard nanocomposite films of nanocrystalline h-Si3N4 / amorphous SiCN. To acquire superhard nanocomposite films with optimal organizational structure and excellent mechanical property, the optimized condition is as follows: the pulse voltage at 550V, the continuance and intermission time of the pulse at 25us, the temperature at 550DEG C, the pressure at 200-220Pa, N2 at 280ml / min,H2 at 700ml / min,Ar at 90ml / min,SiCl4 expressed in H2 load at 150ml / min,the deposition time at 4h.

Description

technical field [0001] The invention belongs to the field of thin film material preparation, and further relates to a method for preparing nanocomposite superhard thin film material by using industrial pulse direct current plasma assisted chemical vapor deposition equipment. Background technique [0002] In 1989, Liu and Cohen theoretically predicted β-C based on the first-principle pseudopotential energy band theory. 3 N 4 Its hardness may exceed that of diamond. However, the synthetic crystalline phase of β-C 3 N 4 Solid materials are very difficult, and to date there are no CNx solid materials in any crystalline phase with crystalline particles large enough to measure their physical, chemical, and mechanical properties. Based on the above research difficulties, adding Si to CNx to form a new type of Si-C-N thin film, relying on the thermodynamic drive of Si, is expected to form a variety of crystalline phases or amorphous structures with excellent performance in Si-C-...

AI Technical Summary

Problems solved by technology

However, the main disadvantage of this method is that the uniformity or visibility of the coating is poor, and it is impossible to achieve uniform coating on the outside, especially the inner surface of complex workpieces.

[0006] There is also the problem of coating uniformity in the radio frequency and DC PCVD methods, and the arc discharge of the DC power supply is inevitable, which is extremely unfavorable for practical applications.

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