Banca de QUALIFICAÇÃO: ANTÔNIO ROBERTO AUGUSTO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANTÔNIO ROBERTO AUGUSTO
DATE: 28/01/2020
TIME: 14:00
LOCAL: Laboratório de Tribologia - NTI/UFRN
TITLE:

EXPERIMENTAL EVALUATION OF THE SURFACE WEAR OF THE CENTRIFUGAL PUMP ROTOR COATED WITH TUNGSTEN CARBIDE MULTI-LAYER FILM IN A VINASSE PUMP UNDER NORMAL CONDITIONS

KEY WORDS:

Centrifugal Pump; Rotor; Coating; Tungsten carbide; HVOF.

PAGES: 115
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The incessant search for better performance in materials, products and processes has led academic circles and companies to undertake and direct investments and personal efforts in the search for new technologies.   The objective of this work is to investigate the main wear mechanisms in a centrifugal pump during the pumping of vinasse with pH 7.4 ± 0.2 used by sugarcane plants in the fertigation of sugarcane fields. A thin film of tungsten carbide (86 %p WC, 10 %p Co, 4 %p Cr) was deposited on the surface of a grey cast iron (ASTMA48Cl30) rotor by the supersonic HVOF (High Velocity Oxygen Fuel) thermal spray process. The morphology and composition of both parts, substrate and coating, were identified and quantified by observation using optical microscopy, scanning electron microscope (SEM) and chemical analysis using dispersive energy electroscopy (EDS). Measurements of roughness, waviness, Brinell hardness, Brinell micro hardness and Vickers micro hardness were performed on the substrate and on the coating presenting results compatible with the researched literature. Following the established route, vinasse was pumped at 33±2oC in a specially developed laboratory bench for 107 cycles tests of a model INI 32-125 centrifugal pump with 140 mm diameter rotor, driven by a 1.0 hp electric motor, speed of 1715 rpm, operating under normal conditions, with minimum cavitation and recirculation, among other phenomena inherent to the process. In the master's defense, the pump was assigned to operate under severe recirculation and cavitation conditions. In this work, after the tests a fully preserved rotor morphology was observed, the lining did not present cracks or visual failures, not even the colloidal solids in suspension produced severe damage on the lining, which was expected.

BANKING MEMBERS:
Presidente - 347080 - JOAO TELESFORO NOBREGA DE MEDEIROS
Externa à Instituição - JULIANA RICARDO DE SOUZA - IFRN
Externo à Instituição - MANOEL FERNANDES DE OLIVEIRA FILHO - IFRN
Interna - 1481705 - SALETE MARTINS ALVES