Aluminum foams are considered as one of the most widely used macroscopic porous materials used in various industries. So far, various processes have been used to produce aluminum foams, an‎d in this regard, a lot of research has been done to develop these processes. The gasar method is one of these methods that is limited due to the conditions an‎d relatively high cost of production. However, compared to other methods, such as direct injection of gas into the melt, stirring of a foaming agent, etc., the production of foam using the gasar method allows for more effective control over the amount of porosity, size an‎d orientation of the holes. The aim of this research was to investigate the possibility of producing a type of aluminum foam with macroscopic porosity using the gas an‎d casting method by thermal decomposition of Viscose Rayon (C6H10O5) an‎d Polypropylene (C3H6) polymers under neutral gas atmosphere an‎d under flux. In this method, the identification of the polymer foaming agent in terms of chemical composition was done using X-ray diffraction an‎d checking the thermal stability of the polymer an‎d its decomposition process with increasing temperature by simultaneous thermal analysis (TG, DSC an‎d DTA). Also, to identify the type of bonds Organic polymer was used by infrared spectroscopy (FT-IR). According to the scanning electron microscopic images of polymer fibers, the average diameter of Viscose fibers was 14.26±1.70 microns an‎d the average diameter of Polypropylene fibers was 22.64±1.70 microns. was estimated. In the foam production method under neutral environment, the effect of the type an‎d amount of polymer an‎d the pressing pressure of the polymer tablet on the apparent density, percentage of porosity an‎d the percentage of the ratio of the area of the holes to the total cross-sectional area of the foam was investigated. The results showed that with the increase in the amount of the agent foaming, the apparent density of the porous piece decreased an‎d the percentage of porosity increased. The highest amount of porosity created under neutral gas atmosphere using Polypropylene polymer is about 20.50±1.21% by volume an‎d using Viscose Rayon polymer about 14.50±1.16% by volume. Also, by increasing the amount of fiber tablet press pressure, the apparent density of the porous piece decreased an‎d its porosity percentage increased. The highest porosity obtained was related to the press pressure of 50 kN/cm2 (with a constant weight percentage of Polypropylene fibers), which is equal to 18.10±0.91% by volume. The results of the production of aluminum foam under coating flux showed that the effect of calcium addition on the formation of porosity in aluminum was very significant, but due to the non-uniform distribution of the porosity an‎d also the connection of the created porosity, this method was not suitable for the production of aluminum foam by the gasar method.

محمود مرآتيان اصفهاني , مسعود پنجه پور

بهزاد نيرومند , مهدي احمديان