In this study, poly­(vinyl alcohol) (PVA) scaffolds are fabricated by an advanced polymer-based freeze-casting method. The sintering process for ceramic-based scaffolds is replaced by cross-linking. It is essential that the selected polymer is water-soluble and cross-linkable. The cross-linking temperature for PVA is 180 °C and it does not require sintering at high temperature as in the typical freeze-casting method. The ultimate compressive strength of PVA scaffolds is measured to be 11 MPa at 75% RH. In the axial direction, the stress–strain curve shows ductility and exhibits a series of jagged breaks after the yield strength. In the radial direction, the scaffold shows compressibility that nature recovery percentage at least exceeded 90% below the strain of 50% and shows complete recoverability via the swelling/deswelling process below the strain of 60%. In summary, the PVA scaffold possesses anisotropic mechanical strength, structural recoverability, and humidity regulating properties, which can be applied as multifunctional materials.

Ac omparative study on the friction and wear properties of semi-solid cast A356 alloy In this study, the friction and wear propertiesofA356 alloy processed via semi-solid casting and conventional casting were experimentally investigated. Experimental results indicatethat under the same experimental conditions the wear of the semi-solid castA356 in mass does not exceed 85 %of that of the conventionally cast A356 alloy. The friction coefficient curve of semi-solid castA356issmoother than that of the conventionally cast A356. The friction coefficient of the semi-solid cast A356 is around 0.53 for stationary friction, less than the 0.59 for the conventionally cast A356. The improvement in the friction and wear properties is mainly aresult of the microstructural change induced by semi-solid processing.