Banca de DEFESA: MARCOS VINICYUS DE ARAÚJO OLIVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : MARCOS VINICYUS DE ARAÚJO OLIVEIRA
DATA : 26/07/2019
HORA: 09:00
LOCAL: Sala 414, do Prédio CTEC, Centro de Tecnologia
TÍTULO:

Effects of the tool material and lubri-cooling techniques on tool lifetime and milled surface of the high-chromium white cast iron

PALAVRAS-CHAVES:

milling, high-chromium white cast iron, tool material, lubri-cooling techniques, three-dimensional wear parameters, residual stress.

PÁGINAS: 140
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Mecânica
SUBÁREA: Processos de Fabricação
ESPECIALIDADE: Processos de Fabricação, Seleção Econômica
RESUMO:

Mechanical components applied to ore crushing, drilling of oil wells and soil plowing need to be manufactured from materials with high resistance to wear, erosion and corrosion. The typical materials applied to described conditions are cold work tool steels, high-speed steels and high-chromium white cast iron (HCWCI). However, the microstructures of these materials are a challenge for machining, particularly the case HCWCI. The HCWCI presents 31 wt% of M₇C₃ carbides in a pearlite or martensitic matrix. Researches about machining of HCWCI are focused on the application of PCBN (Polycrystalline Cubic Boron Nitride) in hard turning due to high wear rates and temperatures on the cutting edges. However, in milling, conditions involve interrupted cutting and the cutting fluids may easily access the cutting region. In the latter case, the coated cemented carbides associated with lubri-cooling techniques may be an alternative to process feasibility. The aim of this work is to evaluate the effects of the tool material and lubri-cooling techniques on tool lifetime and milled surface of the HCWCI. Therefore, two coated cemented carbide grades (PVD-TiAlN e PVD-TiAlN₂) and PCBN grades associated with two lubri-cooling techniques (flood emulsion and liquid nitrogen - LN2) were applied to the milling tests. Three-dimensional wear parameters aided the evaluation of types of wear, aiming to understand the removed material from cutting edges. The results showed the feasibility of the coated cemented carbide as tool material in milling of the HCWIC and that LN₂ has increased twice the tool lifetime, when compared to flood emulsion. Regarding the milled surface, higher values of compressive residual stresses are identified with the use of flood plus fresh cutting edges. However, the use of LN₂ intensifies the shear mechanism during the cutting, preserving the microstructure similar to the original state.

MEMBROS DA BANCA:
Presidente - 1792669 - ADILSON JOSÉ DE OLIVEIRA
Interno - 1545410 - ANDERSON CLAYTON ALVES DE MELO
Externo à Instituição - TIAGO FELIPE DE ABREU SANTOS - UFPE