| Aluminum foam possess these properties as light weight,high specific strength,absorption impact energy,damping,sound absorption.It has a wide range application prospects in the construction,aerospace,automobile production and so on.Melt foaming method is a commonly method for preparing aluminum foam due to its low preparation cost and easy mass production.The foaming agent of melt foaming method is Ti H2,and its decomposition property and dispersibility directly affect the cell structure of aluminum foam:?1?The initial decomposition time of Ti H2 determines the available time of dispersing,and the dispersion time determines the uniformity of the dispersion of Ti H2,which influences the uniformity of the structure of the foam aluminum;?2?The melting point of aluminum and its alloys does not match with the decomposition temperature of Ti H2,and the premature and rapid decomposition of Ti H 2 result in uneven dispersion of Ti H2,which affectes the homogeneity of the cell structure of foam aluminum.In this paper,the oxidation treatment method is used to impro ve the decomposition time and temperature of Ti H2.The dispersibility of the foaming agent was increased by extending the stirring time,and the aluminum foam with uniform cell structure was successfully prepared.The decomposition characteristics and mechanism of oxidized Ti H2 at different temperatures were studied;The influence of dispersing temperature,adding quantity,dispersing time and stirring speed on dispersibility was studied;Meanwhile,the influence of dispersing temperature,adding quanti ty,dispersing time,stirring speed and soaking time on the cell structure of foam aluminum was studied,which lay the foundation for foam aluminum,the main results are as follows:?1?Oxidation treatment has a slow release effect on decomposition of Ti H 2.Ti H2is oxidized at 400?*20h+?470?/485?/500??*4h,and the surface morphology of Ti H2 changes.At the same time the surface of Ti H2 generates a layer thickness of 2.1?m to 2.6?m Tix Oy.Initial decomposition temperature is 575?to 625?,the maximum decomposition temperature is 645?to 675?,the decomposition amount is 2.20%to1.99%.A balance between the delay in gas evolution to 300s and the total gas release to 85ml·g–1 is achieved by oxidation with 400?*20h+485?*4h.?2?The decomposit i on rat e of Ti H 2 increas es wit h t emperature.W hen t he decomposition temperature is 650?,the oxidized Ti H2 with 400?*20h+485?*4h of isothermal decomposition equation is(?9?(?9?=0.003279*?1-?0.7680.?3?Oxidative treatment of Ti H2 with 400?*20h+?470?/485?/500??*4h can increase the available time and effectively improve the dispersibility of the cell structure.The parameters for the foaming agent configuration are as follows:the dispersion temperature of foaming agent is 650?,the amount of foaming agent added is 2.2wt%,the dispersion time is 300s,and the stirring speed is 1400rpm.?4?After the oxidation treatment of Ti H2,the dispersion of available time was increased,and the dispersibility of foaming agent was improved,and the cell structure of foamed aluminum was improved effectively.The parameters for preparing Al-Si6alloy foam configuration are as follows:the dispersion temperature of foaming agent is650?,the amount of foaming agent added is 2.2wt%,the dispersion time is 300s,the stirring speed is 1400rpm,and the foaming time is 16min.The porosity is 77.7%to80.4%,and the average pore diameter is 2.6mm to 3.9mm. |
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