Novel 1.5 GPa-strength with 50%-ductility by transformation-induced plasticity of non-recrystallized austenite in duplex steels.

Needs for steel designs of ultra-high strength and excellent ductility have been an important issue in worldwide automotive industries to achieve energy conservation, improvement of safety, and crashworthiness qualities. Because of various drawbacks in existing 1.5-GPa-grade steels, new development of formable cold-rolled ultra-high-strength steels is essentially needed. Here we show a plausible method to achieve ultra-high strengths of 1.0~1.5 GPa together with excellent ductility above 50% by actively utilizing non-recrystallization region and TRansformation-Induced Plasticity (TRIP) mechanism in a cold-rolled and annealed Fe-Mn-Al-C-based steel. We adopt a duplex microstructure composed of austenite and ultra-fine ferrite in order to overcome low-yield-strength characteristics of austenite. Persistent elongation up to 50% as well as ultra-high yield strength over 1.4 GPa are attributed to well-balanced mechanical stability of non-crystallized austenite with critical strain for TRIP. Our results demonstrate how the non-recrystallized austenite can be a metamorphosis in 1.5-GPa-grade steel sheet design.

Correction: Externally controlled drug release using a gold nanorod contained composite membrane.

Correction for 'Externally controlled drug release using a gold nanorod contained composite membrane' by Kibeom Kim, et al., Nanoscale, 2016, 8, 11949-11955.

Externally controlled drug release using a gold nanorod contained composite membrane.

Versatile drug delivery devices using nanoporous membranes consisting of gold nanorods and dendrimers have been demonstrated to provide light-triggered on-demand pulsatile release from a reservoir containing highly enriched therapeutics for a real patient's needs. The drug release rate is directly correlated with the temperature increase and irradiated energy of a near-IR laser in both static and fluidic devices. This biocompatible platform for on-demand control was further confirmed by in vitro experiments. Interestingly, different responses to stimuli were obtained from each drug in the absence and presence of NIR light, indicating the versatile potential of our on-demand drug delivery system in less-invasive therapies requiring multi-drug delivery strategies. The enhanced delivery system will improve therapeutic efficacy and reduce side effects through regulation of plasma drug profiles.