Applied Technology Lab of Materials in Institute of Solid State Physics, Chinese Academy of Sciences (CAS), consists of three research groups,includingFusheng Hanresearch group, Xiaoying Qinresearch group,Yuqi Wang research group.It is concerned with applied research of materials in several aspects.
FushengHan research group focuses its studies on ultra-light foam metal, high efficiency energy absorbing alloy (Twinning induced plasticity steel) and high damping alloy.
Metal foams are a new, as yet imperfectly characterized, class of engineering materials with low densities and novel physical, mechanical, thermal and acoustic properties.It can be used for sound absorption, heat dissipation, shock absorption, cushioning device. In terms of energy absorption, the large amount of energy dissipated during the plastic deformation of metal foams under compressive loading provides them with great energy absorption capacity and impact resistance. The compressive behavior metal foams is affected by the base material properties, the cell size, and the relative density.Open cell aluminum foams have been electrocoated with nanocrystalline nickel in our study, and the results exhibit that the energy absorption capacity could be increased by a factor of 9 under quasi-static loading, showing great application prospect in shock absorption fields.
Latticealuminum are a kind of new lightweight multifunctional material which has been developed in our group recently. The truss members in lattice materials can be topologically configured to experience predominantly axial stress (tension or compression).In order to obtain a more flexible design in topology structure, we adopt the3D printing and infiltration method to prepare three-dimension multilayerlattice aluminum materials. The results show that pyramidal lattice materials havepreferable mechanical properties to those of conventionalmetal foams.With the adding of core relative density, the compressive strengths and the energy absorption capacity of latticealuminum materials increase obviously.
Magnesium foams have drawn much attention as promising biodegradable bone implant materials due to their outstanding biocompatibility, favorablemechanical properties and similar porous structures close to that of natural bones. In order to produce Mg foams suitable for bone implants, vacuum infiltrationtechnique based on the tailor-madesalt-flour mixture space holders has been developed in our group. Thesalt-flour mixtureparticlesafter high-temperature sintering dissolved rapidly in water due to their porous structures, guaranteeing the weak corrosion and high-purity of magnesium foams. Thespherical pores foams exhibitedusual stress-strain behaviors and nearly isotropic properties. The yield strengths of the foams increased with the decrease of sample porosity, and the relative mechanical properties of foams were mostly dependent on their relative densities, which obeyed a power law relation. Porous magnesium materials with tunable pore structures could be fabricated owing to the flexible forming features of salt-flour mixture, showing great application prospects in bone implant material field.
Twinning induced plasticity (TWIP) steel is currently one of the most attractive materials for structural applications in a variety of engineering fields, such as automobile, high speed rail trains, spacecraft, warship and cryogenic tank, etc., where high plasticity and impact energy absorption capacity are usually required. TWIP is observed in medium stacking fault energy steelsand is characterized by the formation of deformation twins with nanometer thickness. The outstanding mechanical properties combining high strength and ductility can be attributed to its high strain hardening capacity.
Our group mainly focuses on the relations between mechanical properties and extrinsic conditions (sample size, strain rate and temperature, etc.) or intrinsic microstructure feature (inclusions, precipitate, grain size and shape, etc.). Based on those studies, we have found an effective method to enhance both plasticity and strength via controlling the morphology of grains to obtain innovative columnar and columnar/equiaxed mixed grain structures.
XiaoyingQin research group focuses its interests on new thermoelectric materials and devices,sodium sulfur battery.Now it is dedicated to the experiments of Rare earth element doped inducedβ-Zn4Sb3 state density distortion and the improvement of thermoelectric performance.
Yuqi Wangresearch group concerns itself with preparation of molecular beam epitaxy of semiconductor materials and the design and preparation of new functional semiconductor materials.Now the specific researchesareas follows: thin film of Silicon nitride injection and gas phase deposition, the interface state between gallium nitride, EL2 center deep level defects in the one-dimensional nanowire of Gallium arsenide, and so on.