Mechanical Properties of Highly Porous NiTi Alloys

被引:31
作者
Bram, Martin [1 ]
Koehl, Manuel [1 ]
Buchkremer, Hans Peter [1 ]
Stoever, Detlev [1 ]
机构
[1] Forschungszentrum Julich, Inst IEF 1, D-52425 Julich, Germany
关键词
fatigue; mechanical properties; metal injection molding; porous NiTi; powder metallurgy; space-holder technique; SHAPE-MEMORY ALLOYS; BEHAVIOR; IMPLANTS; FABRICATION; REPLICATION; POROSITY;
D O I
10.1007/s11665-011-9854-y
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Highly porous NiTi alloys with pseudoelastic properties are attractive candidates for biomedical implants, energy absorbers, or damping elements. Recently, a new method was developed for net-shape manufacturing of such alloys combining metal injection molding with the application of suitable space-holder materials. A comprehensive study of mechanical properties was conducted on samples with a porosity of 51% and a pore size in the range of 300-500 mu m. At low deformations < 6%, fully pronounced pseudoelasticity was found. Even at higher strains, a shape recovery of maximum 6% took place, on which the onset of irreversible plastic deformation was superposed. Results of static compression tests were also used to calculate the energy-absorbing capacity. Fatigue of porous NiTi was investigated by cyclic loading up to 230,000 stress reversals. The failure mechanisms responsible for a reduction of shape recovery after an increased number of load cycles are discussed.
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页码:522 / 528
页数:7
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