Although natural fibre-based thermoplastic composites (NFCs) have the advantages of environmental compatibility and low cost, their mechanical properties are still relatively poor. Hybridization with basalt fibres (BFs) can broaden the industrial applications of NFCs. Hybrid composites were manufactured by means of interlayer hybrid reinforcement; that is, the hybrid composites were prepared by the lamination moulding of BF prepregs and hemp/polylactide fibre (HF/PLA) felts. The effects of cryogenic treatment and interfacial modification in BF hybridization on the mechanical properties of HF/PLA composites were investigated. The study revealed that the hybridization of BFs with hemp fibres (HFs) significantly increased the mechanical properties of composites, and the cryogenic treatment and interface modification of BFs also improved the performance of hybrid composites. Compared with those of untreated BF-reinforced composites (UBF/HF/PLA), the tensile strength, flexural strength, and impact strength were increased by approximately 28.5% (120.82 MPa), 44.6% (90.29 MPa), and 192.1% (61.0 kJ/m2), respectively.

Calcium (Ca), with abundant and cheap reserves, is a potential element to facilitate the further application of Mg-Al-Sn based alloys. Here, effects of Ca content on the microstructure and tensile properties of Mg-2.0Al-0.8Sn (wt.%) alloys were systematically studied. The experimental results illustrated that the strength, ductility and isotropy of the alloys improved simultaneously with the increase of Ca content. The better ductility and isotropy could be contributed to the weakened texture via particle stimulation nucleation mechanism. The higher strength benefited from the combination of finer grains, more precipitates and residual dislocation density. Eventually, the Mg-2.0Al-0.8Sn-0.5Ca (wt.%) alloy showed the best room-temperature balance of strength and ductility with a yield strength of ∼226.0 MPa, an ultimate tensile strength of ∼282.4 MPa and a fracture elongation of ∼20.2%, which has huge potential as an applicable low-cost high-performance magnesium alloy.