Banca de QUALIFICAÇÃO: LÉLIO GOES DE ALMEIDA FILHO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LÉLIO GOES DE ALMEIDA FILHO
DATE: 29/02/2024
TIME: 10:00
LOCAL: meet.google.com/imj-xzus-bcf
TITLE:

MACHINABILITY OF NEAR NET SHAPE (NNS) MOLDS OF HIGH CHROMIUM WHITE CAST IRON UNDER CRYOGENIC CONDITION 2024

KEY WORDS:

Machinability, Near Net Shape, High Chromium White Cast Iron , Liquid Nitrogen

PAGES: 63
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Processos de Fabricação
SPECIALTY: Matrizes e Ferramentas
SUMMARY:

High-chromium white cast iron (HCWCI) is an abrasion resistant (AR) cast iron typically containing 12 to 25% Cr and 2 to 3.6% C, in addition to other alloying elements. Its microstructure is comprised of hard and wear-resistant M7C3 metal carbides (~1400 HV), with a matrix that can be ferritic, pearlitic, bainitic, ausferritic, martensitic austenitic or usually a mixture. It is characterized by its good corrosion resistance and toughness, presenting excellent performance in a wide range of applications, such as hydraulic pump housing and turbine, agricultural plow, mixer blade for concrete mixing, and coal-crushing rollers. Furthermore, HCWCI parts can be easily obtained in small to medium foundries, which can mean the possibility of on-demand manufacturing and recycling. Thereby, considering its good hardness, abrasive resistance and other tribological properties, in addition to the possibility of on-demand manufacturing and recycling, HCWCI could also be an economical and sustainable alternative for manufacturing of plastic injection molds used in the automotive industry. Currently, P20 plastic mold tool steel is the main material used for this application, which has a high purchase price, besides being produced on batch. In this context, this work presents a part of a study that aims at investigating the possibility of using HCWCI as raw material to manufacture automotive plastic injection molds. Thus, end milling trials assisted by compressed air and liquid nitrogen (LN2) have been carried out on four HCWCI blocks with different composition and microstructure, i.e., 19% Cr eutectic, 19% Cr hypoeutectic, 26% Cr eutectic, and 26% Cr hypoeutectic. Additional milling trials have also been carried out on a hardened P20 block under the same cutting parameters and conditions for comparison. As output variable, cutting tool wear has been monitored using an optical microscope. Additionally, worn cutting tools have been analyzed with a scanning electron microscope to identify the wear mechanisms.

COMMITTEE MEMBERS:
Interno - 1545410 - ANDERSON CLAYTON ALVES DE MELO
Interno - 1938946 - NICOLAU APOENA CASTRO
Interna - 1481705 - SALETE MARTINS ALVES
Externo ao Programa - 1792681 - ULISSES BORGES SOUTO - UFRN