Alumíniumhab magú, szálerősített polimer mátrixú szendvicsszerkezet vizsgálata statikus és dinamikus igénybevételek esetén = Investigation of Aluminium Foam Core Fiber Reinforced Polymer Matrix Sandwich Structure at Static and Dynamic Loads

Cikkünkben bemutatjuk a fémhabok szerkezeti felépítését, gyártási, felhasználási módjait, vizsgálati lehetőségeit. Kitérünk a fémhab vágási eljárással kapcsolatos, valamint a szendvicsszerkezetek és ezek gépszerkezettani alkalmazásával kapcsolatos kutatási célkitűzésekre

CFRP-aluhab®-CFRP szendvics szerkezetű kompozit anyag fúrása = Drilling of CFRP-Aluhab®-CFRP Sandwich Structure

Napjainkban az ipar egyre több területén használnak különleges anyagokat. Ezek az anyagok általában kiváló mechanikai tulajdonságaikkal rendelkeznek. Az alumíniumhab is ezek közé az anyagok közé tartozik. Ez az anyag rendkívül könnyű és emellett nagy teherbírással rendelkezik. Az anyag rezgéselnyelő képessége, a cellás szerkezetének köszönhetően meglehetősen jó. Kutatásunk célja feltárni az alumíniumhab forgácsolásának lehetőségeit

Fracture Behavior of Metal Foam Made of Recycled MMC by the Melt Route

Metal foam was made from recycled MMC precursor by the melt route. The original starting material was an Al-9Si alloy containing 20 vol% of SiC particles (10 mm), which are used to stabilize the foam during the foaming process. The starting material has been used to make foam parts from which the residue was recycled and refoamed. During the (re)foaming process Fe is present in the melt. During solidification of the foam, -AlSiFe plates are formed with the surplus of Si and Al present in the alloy. These plates run through the entire thickness of the cell wall (40-50 mm) and their length ranges between 50 and 200 mm. During in-situ tensile tests fracture initiates in the -AlFeSi plates and propagates through other -AlFeSi plates leading to brittle fracture of the cell walls

Compressive characteristics of metal matrix syntactic foams

The compressive behaviour of eight different metal matrix syntactic foams (MMSFs) are investigated and presented. The results showed that the engineering factors as chemical compositions of the matrix material, the size of the microballoons, the previously applied heat treatment and the temperature of the compression tests have significant effects on the compressive properties. The smaller microballoons with thinner wall ensured higher compressive strength due to their more flawless microstructure and better mechanical stability. According to the heat treatments, the T6 treatments were less effective than expected; the parameters of the treatment should be further optimized. The elevated temperature tests revealed ~30% drop in the compressive strength. However, the strength remained high enough for structural applications; therefore MMSFs are good choices for light structural parts working at elevated or room temperature. The chemical composition – microballoon type – heat treatment combinations give good potential for tailoring the compressive characteristics of MMSFs

Fracture Behavior of Metal Foam Made of Recycled MMC by the Melt Route

Metal foam was made from recycled MMC precursor by the melt route. The original starting material was an Al-9Si alloy containing 20 vol% of SiC particles (10 μm), which are used to stabilize the foam during the foaming process. The starting material has been used to make foam parts from which the residue was recycled and refoamed. During the (re)foaming process Fe is present in the melt. During solidification of the foam, β-AlSiFe plates are formed with the surplus of Si and Al present in the alloy. These plates run through the entire thickness of the cell wall (40–50 μm) and their length ranges between 50 and 200 μm. During in-situ tensile tests fracture initiates in the β-AlFeSi plates and propagates through other β-AlFeSi plates leading to brittle fracture of the cell walls.

Acoustic-Pressure-Assisted Engineering of Aluminum Foams

Shaping metals as a foam modulates their physical properties, enabling attractive applications where lightweight, low thermal conductivity, or acoustic isolation are desirable. Adjusting the size of the bubbles in the foams is particularly relevant for targeted applications. Herein, a method with a detailed theoretical understanding of how to tune the size of the bubbles in aluminum melts in situ via acoustic pressure is provided. The description is in full agreement with the high-rate 3D X-ray radioscopy of the bubble formation. The study with the intriguing results on the effect of foaming on electrical resistivity, Seebeck coefficient, and thermal conductivity from cryogenic to room temperature is complemented. Compared with bulk materials, the investigated foam shows an enhancement in the thermoelectric figure of merit. These results herald promising application of foaming in thermoelectric materials and devices for conversion of thermal energy