Fabrication of Closed-Cell Magnesium Composite Foam with Fine and High Roundness Pore Structure

Nannan Wang,Xingchuan Xia,Weimin Zhao,Jing Wang

doi:10.11648/j.sr.20190704.12

Abstract

Though metal foams possess excellent overall performances, its performances behave quite different due to its apparent aperture difference of pores diameter, pores roundness and significant macrostructure flaws, such as sharp edged pores and incomplete cell walls. It is meaningful to reduce macrostructure defects or improve pores structure uniformity of metal foams from the view point of practical applications. In this work, different thickening agents were added into AZ31B magnesium composite foams to balance foaming process and improve the homogeneity of pore diameter, pore roundness and cell wall integrity. The results showed that pore diameter, roundness of the pores and integrity of cell walls were obviously influenced by thickening agents. Based on a large number of experimental results, calcium granules and magnesium cerium intermediate alloy were used to control the number and morphology of solid particles in magnesium melt, and a kind of magnesium composite foams with fine roundness pores and complete cell wall structure were obtained.

Highlights

Due to its low density, high strength, good noise insulation, excellent acoustic absorptivity and vibration reducing performance, closed-cell metal foams have been widely used in traffic transportation, aerospace, navigation, explosion shock absorption and noise abatement engineering fields
Braszczyńska-Malik et al prepared magnesium composite foam by negative pressure infiltration technique using fly ash cenospheres as pore fillers, and the interface integration between magnesium matrix and fly ash cenospheres with Ni-P coating was investigated, the results showed that adding fly ash cenospheres with Ni-P coating would effectively avoid the cenospheres be penetrated, increase the porosity and obtain fly ash cenospheres homogeneous distribution in magnesium composite foam [9, 10]
Pores roundness is an important factor to evaluate the mechanical properties of magnesium composite foam

Summary

Introduction

Due to its low density, high strength, good noise insulation, excellent acoustic absorptivity and vibration reducing performance, closed-cell metal foams have been widely used in traffic transportation, aerospace, navigation, explosion shock absorption and noise abatement engineering fields. Inhomogeneous spatial structures and flaws deteriorate its overall performances and limit its applications as structural and functional materials [2,3,4,5]. To solve these problems, Bhogi et al carried out a group of contrast experiments about the effect of thickening step on the foaming stabilization of Al-Mg alloy using melt foaming method. Braszczyńska-Malik et al prepared magnesium composite foam by negative pressure infiltration technique using fly ash cenospheres as pore fillers, and the interface integration between magnesium matrix and fly ash cenospheres with Ni-P coating was investigated, the results showed that adding fly ash cenospheres with Ni-P coating would effectively avoid the cenospheres be penetrated, increase the porosity and obtain fly ash cenospheres homogeneous distribution in magnesium composite foam [9, 10]. Anbuchezhiyan et al reported that externally-added hollow glass microspheres

Methods

Results

Conclusion