Mechanical hardness testing is fundamental in the evaluation of the mechanical properties of metallic materials due to the fact that the hardness values allow one to determine the wear resistance of the material involved, as well as the approximate values of its ductility, flow tension, among a number of other key characteristics. As a result, the main objective of the present work has been the development and ...
Drilling carbon/epoxy laminates is a common operation in manufacturing and assembly. However, it is necessary to adapt the drilling operations to the drilling tools correctly to avoid the high risk of delamination. Delamination can severely affect the mechanical properties of the parts produced. Production of high quality holes with minimal damage is a key challenge. In this paper, delamination caused in lamina...
Fibre reinforced plastics are increasing their importance as one of the most interesting groups of material on account of their low weight, high strength and stiffness. To obtain good quality holes, it is important to identify the type of material, ply stacking sequence and fibre orientation. In this paper, the drilling of quasi-isotropic hybrid carbon+glass/epoxy plates is analyzed. Two commercial drills and a...
A utilização crescente de materiais compósitos nos mais variados domínios coloca novos desafios no projecto de ferramentas de corte dedicadas a este tipo de materiais, ao invés da tradicional adaptação das ferramentas desenvolvidas para materiais metálicos. Neste artigo apresenta-se um estudo comparativo de geometrias de broca com o objectivo de reduzir o dano associado. Para tal, são analisadas as forças desen...
Welding dilution is the chemical composition modification of the weld metal, caused by the portion of base metal that suffers melting and starts to form the fusion zone. Its measure is given by the percentage of the base metal that takes part in the formation of the weld filet, and it varies according to the used welding process, type of join, pre-heat temperature, consumable, parameters of welding, among other...
The distinctive characteristics of carbon fibre reinforced plastics, like low weight or high specific strength, had broadened their use to new fields. Due to the need of assembly to structures, machining operations like drilling are frequent. In result of composites inhomogeneity, this operation can lead to different damages that reduce mechanical strength of the parts in the connection area. From these damages...
Duplex stainless steel presents special mechanical properties such as, for example, mechanical and corrosion strength, becoming competitive in relation to the other types of stainless steel. One of the great problems of duplex stainless steel microstructural changes study is related to embrittlement above 300ºC, with the precipitation of the ’ phase occurring over the ferritic microstructure. Aimi...
This work shows the results of laminate drilling using an Nd-YAG laser, a nonconventional method. Advantages in damage reduction are discussed.
The subject of this work is the study of drilling conditions and tool geometry in order to minimize delamination damage. Delamination is evaluated by enhanced radiography and damage criteria applied to compare different tools and cutting parameters.
Financiadores do RCAAP | |||||||
![]() |
![]() |
![]() |
![]() |
![]() |
![]() |