Preparation Process Design And Research Of Aluminum Foam Sandwich

Aluminum foam sandwich panel is a composite based on an aluminum foam core and two dense metal cover sheets.It achieves the combination of properties of metal foams and dense metal,such as light weight,good strength,high specific strength and superior impact resistance,which has received increased attention in recent years in military,aerospace,transportation and construction fields.Manufacturing methods of aluminum foam sandwich panel have been studied by numerous researchers abroad and large-scale al-aluminum foam sandwich panels with metallurgical bonding has been successfully produced.However,manufacture of aluminum foam sandwich panel with metallurgical bonding is still a challenging issue,especially for steel-aluminum foam sandwich panel.In this work,large-scale steel-aluminum foam sandwich panel with metallurgical bonding was manufactured based on liquid mixing andsecondary foaming methods.To manufacture the product,primary devices used were designed and installed.And the surface of aluminized steel treated by hot spraying,the interface of foamable precursor and the joint of steel/foams were analyzed.The main contents are as follows.(1)Foamable precursor was prepared using liquid mixing method by treating SiC and TiH2 particles.The results showed that the porosity of the precursor had a tendency to decrease with increased SiC content;TiH2 treated at 500? for 5h could meet the requirements to manufacture aluminum foam sandwich panel.(2)Steel cover sheet was treated by thermal spraying using aluminum and SEM results revealed that mechanical bonding dominated in the interface region between the aluminized coating and foam;preliminary diffusion bonding was achieved between the aluminum coating and the precursor when hot pressing technology was used while it was still mechanical bonding between the steel plate and aluminum coating.In aluminum foam sandwich manufactured by rapid foaming,aluminum coating formed by thermal spraying disappeared.A 15 ?m thick Fe-Al intermetallic compound layer was formed in the interface between the steel plate and foam,revealing that metallurgical bonding was achieved by elemental diffusion.(3)To manufacture aluminum foam sandwich panel with metallurgical bonding,a rotary roasting kiln,that can meet the requirements of oxidation treatment of TiH2,was designed.Hot pressing machine meeting the requirements to bonding steel plate and precursor with large scale was also designed.Besides,infrared rapid foaming device was installed to manufacture large-scale aluminum foam sandwich panels with metallurgical bonding.(4)Using liquid mixing andsecondary foaming methods and the devices designed,aluminum foam sandwich panels with sizes 180 mm×180 mm×14mm was successfully manufactured,and the bonding between the cover plate and foam was confirmed metallurgical bonding.When subjected to quasi-static bending,sandwich panel with metallurgical bonding failed without interfacial delamination,the deformation/failure modes were dominated by cracking,collapse and densification of foams,and bonding strength of the steel/aluminum interface was higher than that of the aluminum foam core.