Banca de QUALIFICAÇÃO: JOÃO FREIRE DE MEDEIROS NETO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : JOÃO FREIRE DE MEDEIROS NETO
DATE: 11/03/2024
TIME: 07:20
LOCAL: meet.google.com/tdw-qbmd-mpb
TITLE:

Study of the Kinetics of Plasma Deposition through Cathodic Cylinder Deposition

KEY WORDS:

Cathodic Cylinders, Deposition, Plasma

PAGES: 120
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

This study introduces the technique of composite film deposition through cathodic cylinders plasma deposition (CCyPD). This technique is a variation of the existing cage cathodic deposition system (CCPD), which replaces the holes in the cage with cylinders of composite materials, allowing for the simultaneous deposition of various types of materials using treatment parameters already used in conventional cage cathodic deposition, which enables and facilitates the implementation of this technique. Thus, this work presents three different depositions that used the cathodic cylinder technique. In the first treatment, MoS2 cylinders were used to deposit a 2D lubricating film that favors sliding planes and reduces the coefficient of friction. In the second treatment, composite powder cylinders containing TiO2, Nb2O5, and C (graphite) were used, with hydrogen and nitrogen flow that favor the reduction of oxides and the deposition of a hard film based on titanium and niobium nitrides and carbides. In the third treatment, the two types of cylinders used previously were used simultaneously to deposit a hard and lubricating film. The treated samples showed a lower wear rate, smoother/lower coefficient of friction, and a slightly reduced tribological test temperature when compared to untreated samples, due to the presence of a molybdenum disulfide (MoS2) phase, which acts as a  solid lubricant agent in sliding contact applications.The treatments that used hard film deposition resulted in a three to four times increase in hardness, and TiN, NbN, NbC were formed. There was also a highlight for the reduction of wear, which decreased from 10 to 50 times for samples treated at higher temperatures.

COMMITTEE MEMBERS:
Externo à Instituição - MAXWELL SANTANA LIBÓRIO - UFRN
Externo ao Programa - 1938946 - NICOLAU APOENA CASTRO - nullInterno - 1350249 - RUBENS MARIBONDO DO NASCIMENTO
Interna - 1481705 - SALETE MARTINS ALVES
Interno - 2550377 - THERCIO HENRIQUE DE CARVALHO COSTA