A stereocomplexation constructed between poly (D-lactide) grafted hydroxyapatite and poly (L-lactide): Toward bioactive composite scaffold with enhanced interfacial bonding

Poly (L-lactide) (PLLA)/hydroxyapatite (HAP) composite scaffold is expected to combine the favorable compatibility and processability of PLLA with the excellent bioactivity and osteoconductivity of HAP. Unfortunately, poor interfacial bonding between...

Effects of Sintering Temperature on Microstructure and Wear Properties of Al2O3 Particle Reinforced Al Composites

Al2O3 particle reinforced aluminum composites were prepared by powder metallurgy process. The effects of sintering temperature on microstructure and tribological characteristic were investigated with the combination of experimental results and theoretical analysis. The composite sintered at 550 oC shows high relative density and strong interfacial bonding, whereas the composites sintered at lower and higher temperature indicate no interfacial bonding and poor interfacial bonding, respectively. The surface morphology observed by scanning electron microscopy (SEM) indicated that the grains of the Al-based composites sintered at 550 oC were uniform and compact, which were in agreement with the properties of high density and tribological properties.

Synthesis of Al7075 Alloy/Al2O3 Composite and Corrosion Study

Al7075alloy and Al2O3 powders were synthesized via high-energy ball mill for 5 h. Al7075alloy powders were mixed with Al2O3 ranging from 5 to 15 vol. %, compacted by cold uniaxial compaction at 400 MPa. The green pellets were degassed at 350 oC for 30 min, and then sintered in the temperature of 600 oC under argon atmosphere for 120 min. It was shown that better density, vickers micro hardness and corrosion resistance were achieved up to 10 vol. % due to uniform distribution of Al2O3 particles throughout matrix. Beyond 10 vol. %, Al2O3 resulted in clustering, porosity and poor interfacial bonding and their properties.