GCRIS

Now showing 1 - 2 of 2

The Effects of Sic Particle Addition on the Foaming and Mechanical Behavior of Aluminum Closed-Cell Foams Produced by Foamming of Powder Compacts
(Izmir Institute of Technology, 2010) Yüksel, Sinan; Güden, Mustafa
The maximum and linear expansions of a large number of SiC particle/Al powder compacts of varying average SiC particle size (0.03-67 .m), weight percentage (wt%) and size distribution and Al compacts without particle addition were experimentally determined. The powder compacts showed varying expansion values depending on the size, wt% and size distribution of the particles. The linear and maximum expansions for small size SiC particle additions were found to be relatively high at relatively low wt%'s (5 wt%) and decreased with increasing wt% of the particles from 5 wt% to 10 and 15 wt%. The compacts with small average particle size but wider particle size distribution showed higher expansions than the compacts with the similar average particle size but narrower particle size distribution, showing the importance of the particle size distribution on the expansions of Al compacts. The foam expansions were further shown to increase with SiC particle addition until about a critical cumulative particle surface area; however, the expansions decreased significantly at increasingly high cumulative particle surface areas due to the excessive increase in the compact viscosity. For the investigated powder compacts, the optimum wt% of SiC addition was determined, as a function particle size, based on the critical cumulative particle surface area. Compression tests showed that the density of the foam was the most effective parameter in increasing the plateau stresses. Microscopic analysis showed that the main deformation mechanism in Al and SiC/Al foams was the cell wall bending, i.e. cell edges buckled over cell walls. This resembled the deformation characteristics of the open cell foams. It was finally shown that SiC particle addition increased the foam plateau stresses over those of Al foam without particle addition, which was mainly attributed to the reduced fraction of the metal on the cell edges.
Optimization of the Axial Crushing Behavior of Closed-Cell Aluminum Foam Filled Welded 1050 Al Square-Cross Section Crashboxes
(Izmir Institute of Technology, 2009) Toksoy, Ahmet Kaan; Güden, Mustafa
The crushing behavior of partially Al closed-cell foam (Alulight AlSi10) filled 1050H14 Al crash boxes was investigated at quasi-static and dynamic deformation velocities. The quasi-static crushing of empty and filled boxes was further simulated using LS-DYNA. Finally, the crushing of partially foam filled 1050H14 crash boxes was optimized using the response surface methodology. The used optimization methodology was also applied to the boxes made of a stronger Al alloy, 6061T4 Al, and filled with a higher strength Al foam, Hydro Al closed cell foam, in order to clarify the effect of box material and foam filler strength on the crushing behavior of the filled boxes. Within the investigated tube thickness and foam relative density range, the energy absorption of 1050H14 boxes was optimized at 3 mm wall thickness and 0.1114 (Alulight) and 0.0508 (Hydro foam) foam filler relative density. The increase in specific energy absorption of 1050H14 crash box was 5.6% with Alulight and 21.9% for Hydro foam filling. The SEA values of empty, partially and fully foam filled boxes were predicted as function of box wall thickness between 1 and 3 mm and foam filler relative density between 0 and 0.2, using the analytical equations developed for the mean crushing loads. The analysis indicated that both fully and partially foam filled boxes were energetically more efficient than empty boxes above a critical foam filler relative density. Partial foam filling however decreased the critical foam filler density at increasing box wall thicknesses.

Phd Degree / Doktora

Browse

Filters

Settings

Sort By

Results per page

Search Results