فهرست مطالب احسان زنده باد

Aluminum foam sheets produced by accumulative roll-bonding process via decomposition of a blowing agent، have a great capability for fabricating sandwich structures including aluminum foam cores. A comprehensive design of these structures demands the optimization of foaming parameters، particularly foaming heat treatment. Using preheated furnaces as alternative to infrared image furnaces، which are commonly used for foaming heat treatment، could lead to easier and less expensive foam production. Optimizing the parameters for such heat treatment is the main subject of this study. In order to achieve a preform for foaming heat treatment tests، TiH2 powders were distributed in the aluminum matrix by 7 passes of repeated roll-bonding and cutting. The fabricated preforms were heat treated to convert to the foams in a preheated resistance furnace. Optimized heat treatment parameters for achieving the best combination of porosity and cell morphology were extracted. The best result was aluminum foam with 37. 2 % porosity.

Aluminum and its alloys duo to their low density, good accessibility and ease of converting to foam, become the most used materials in manufacturing of metallic foams. In this study Accumulative Roll-Bonding process has been utilized for distributing TiH2 powders, as foaming agent, in the structure of an aluminum sheet. Then, via a suitable heat treatment the powders were decomposed and the preform was converted to foam. Also, using the uniaxial compression test, compressive strength of the fabricated foam in different loading directions has been investigated and a correlation between compressive strength and porosity and loading direction has been observed. Maximum compressive strength of 21.08 MPa for foam of porosity 30% in the rolling direction (RD) was measured and increasing the porosity, a decrease in compressive strength was observed. The compressive behavior of the fabricated foam was different in three loading directions.