9 documents found, page 1 of 1
A Comparative Thermoacoustic Insulation Study of Silica Aerogels Reinforced wit...
Linhares, Teresa; Carneiro, Vitor H.; Pessoa de Amorim, Maria T; Durães, LuisaSilica aerogels are highly porous materials with exceptional thermal insulation performance. They become even more attractive if combined thermal and acoustic insulation is achieved. Silica aerogel composites reinforced with fibres are an ingenious way to surpass the fragility stemmed from the aerogel's intrinsic porosity, and textile fibres are good sound absorption materials. Reclaimed fibres are a relatively...
Impact of the ultrasonic-assisted casting of an AlSi7Mg alloy on T6 heat treatment
Gomes, Inês V.; Grilo, José; Carneiro, Vitor H.; Puga, HélderIn this work, the effect of ultrasonic vibration during solidification on the aging kinetics of an AlSi7Mg alloy is investigated. With the ultrasonic equipment coupled to the mold walls, melt treatment was performed by two approaches: (i) fully above liquidus (>635 ◦C); and (ii) in the full range between liquidus and solidus (630 ◦C→ 550 ◦C). Cast samples were then subjected to T6 heat treatment for different a...
The influence of precipitation hardening on the damping capacity in Al–Si–Mg ca...
Carneiro, Vitor H.; Grilo, José; Soares, Delfim; Duarte, Isabel; Puga, HélderAn A356 alloy is a classic casting light alloy, which is able to be processed into complex geometrical shapes with tailored static and dynamic mechanical properties. As a promising material to reduce fuel and energy consumption in future vehicle designs, there is an interest in understanding the impact of heat treatments on the damping capacity of this alloy. The Granato–Lücke theory is used to detail the force...
Casting A356+SiCp with ultrasonically treated melts: effect reinforcement and p...
Carneiro, Vitor H.; Grilo, J.; Puga, H.; Duarte, I.; Jesus, C.Low mass fractions (0.05 wt%) of SiC micro sized particles have been added to an A356 melt and dispersed by ultrasonic vibration to study their impact on the microstructural morphology of cast samples. It is shown that the ultrasonic melt treatment at 680°C can promote a homogenizeddistribution of the reinforcement while also degassing the melt and induces a moderate grain refinement. Even though SiC may act as...
The influence of precipitation hardening on the damping capacity in Al–Si–Mg ca...
Carneiro, Vitor H.; Grilo, José; Soares, Delfim; Duarte, Isabel; Puga, HélderAn A356 alloy is a classic casting light alloy, which is able to be processed into complex geometrical shapes with tailored static and dynamic mechanical properties. As a promising material to reduce fuel and energy consumption in future vehicle designs, there is an interest in understanding the impact of heat treatments on the damping capacity of this alloy. The Granato–Lücke theory is used to detail the force...
Development and characterization of in-situ sandwich panels with aluminum alloy...
Caldeira, Ana Sofia; Vesenjak, Matej; Carneiro, Vitor H.; Krstulović-Opara, Lovre; Duarte, IsabelThe aluminum alloy foams have been explored to be used in energy absorption applications that require lightweight structures with high strength-to-weight and stiffness-to-weight ratios, high impact energy absorbing capacity, and good damping of noise and vibration. The metal foams are usually applied as core and/or as filler of sandwich panels and thin-walled structures. The purpose of this paper is to develop ...
Development and characterization of aluminum alloy foam - cork hybrid structures
Sousa, João D. P.; Pinto, Susana C.; Vesenjak, Matej; Carneiro, Vitor H.; Krstulović-Opara, Lovre; Marques, Paula A. P.; Duarte, IsabelCellular solids and porous materials have been considered as one of the most suitable lightweight multifunctional materials for a wide range of commercial and industrial applications, e.g. in medicine, military. Their use contributes to an immediate and significant weight reduction and material savings of the components but also to multifunctionality due to their 3D cellular structures (open-cells or closedcell...
Temperature variability of Poisson’s ratio and its Influence on the complex mod...
Carneiro, Vitor H.; Puga, HélderDynamic mechanical analysis (DMA) is the usual technology for the thermomechanical viscoelastic characterization of materials. This method monitors the instant values of load and displacement to determine the instant specimen stiffness. Posteriorly, it recurs to those values, the geometric dimensions of the specimen, and Poisson’s ratio to determine the complex modulus. However, during this analysis, it is assu...
Effect of internal structure in the compression behavior of casted Al/LECA comp...
Puga, Hélder; Carneiro, Vitor H.; Barbosa, J.In this paper, low-cost, aluminum-based composite metal foams are produced by the gravity die casting technique using lightweight expanded clay (LECA) as space holders. The influence of the voids generated by LECA particles on the syntactic composite samples density and mechanical behavior is characterized by quasi-static uniaxial compression. It is shown that smaller particles generate higher relative densitie...