Improvement studies of a pulsed DC PECVD system with additional cathode for DLC films deposit high adherence and enhanced properties on metal substrates

Abstract

The research of nanostructured materials in the coatings form or thin films with advanced properties it has enabled the development of new scientific and technological advance in different segments of academia and the productive sector. Among these materials, hydrogenated amorphous carbon (aC:H), also known DLC (Diamond-like Carbon) has been highlighted because of its excellent properties such as high strength, high hardness, low friction coefficient , among others. A challenge for researchers of surface engineering is to deposit DLC films of high adhesion to metal substrates for industrial service applications where the studies of scale and automation are necessary. Automation dictates here is not restricted to automate an equipment, but understand how it works the process of deposition of thin films of DLC -chemically and physically- on different substrates. It is intended that the system allows the study of the properties of these thin films in different positions within reactor in order to maximize the use of gas components via flow control, pressure, temperature, percentage entres the precursor gases, etc. Thus, this line of research, this post-doctoral project aims to identify and better understand the issues involved in adhesion between DLC films and different metal substrates, especially with the growing use of XPS and SIMS techniques, and techniques conventionally used. For this, the pulsed DC technique PECVD (Plasma Enhanced Chemical Vapor Deposition) with additional cathodes, although little explored so far is used for the deposition of DLC films in large areas and large internal volumes of a specially prepared ballast for this work . Therefore, the primary design contribution is the detailed study of this technique order to' establish the deposition parameters necessary for the synthesis of high adhesion DLC films and low residual stresses and establish a correlation with the dimensions and shapes of the additional cathode which is mainly responsible for the high grip. As part of the characterization studies of DLC films, the structural, morphological, mechanical and tribological of synthesized samples will be determined as the dimensions of the additional cathode, which for the first time is being studied to be fully understood. Finally emphasize that this system was patented by the reaserch group and the proponent of this request is co-author, where the first we used a PECVD system to operate at pressures below 10-3 Torr, a process of film growth via PECVD on a non collisions, providing high adhesion between the film DLC and its substrates. Automation is only a need to be achieved during studies, where different properties of the DLC film to be the same for the entire reactor volume, which requires a greater control of the parameters involved in the discharge process, including gas flow in different regions of the reactor split between the precursor components, the applied voltage (pulse width, frequency and amplitude). Remember, finally, that the parameters of scale and properly determined automation, as expected, this system is being made available to the national and international market for the first time as an innovation in advanced instrumentation, high impact and as a the most important by-products of DLC studies by INPE Dimare Reaserch Group. (AU)