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Cubic boron nitride (cBN)-based composites were fabricated using AlN-Al-Ni binders at high pressure and high temperature (HPHT). Effects of binder content and temperature on phase composition, microstructure and mechanical properties of cBN-based composites were investigated. Abrasive ratio was measured using a new method. Almost all Al reacted with cBN during sintering, resulting in AlN as well as AlB 2 phases, while remaining Al and Ni formed intermetallic compounds. At 1500 °C, the reaction reached its maximum. Excellent relative density, flexural strength and fracture toughness of composites, sintered with 17 wt% binder, were 99.6%, 661 MPa and 7.19 MPa m 1/2 , respectively. However, the optimum value of hardness and abrasive ratio of composites at binder content of 13 wt% were 47.92 GPa and 2.99, respectively. [ABSTRACT FROM AUTHOR]

Composite nanomaterials have recently amassed increasing interests in biomedical applications because of the limited function of pure material. This work designed a uniform and multifunctional nanoplatform (NPF) probe composed of superparamagnetic ferroferric oxide (Fe 3 O 4) cluster as core and mesoporous silica embedded with CdTeS quantum dots (QDs) as middle layer wrapped by the outer silica shell. The Fe 3 O 4 cluster core served as the magnetic and photothermal agent, and the CdTeS QDs served as the fluorescence-labelling agent. For the first time, quantities of QDs were embedded into the mesoporous silica based on electrostatic interaction and physical absorption, which are superior to the traditional crosslink-loading method. The NPF probes were successfully internalized into cancer cell with the decoration of folic acid. Transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), fluorescence spectrophotometer, and temperature detector were used to detect the NPF probe. The NPF probe was verified to possess excellent magnetic, fluorescent, and photothermal properties suitable for multiple medical applications. More importantly, a collaborative diagnosis–treatment probe that combines fluorescence labelling and photothermal therapy exhibited the perfect behaviour of labelling and destroying cancer cells in vitro. [ABSTRACT FROM AUTHOR]

Composites consisting of cubic boron nitride (cBN) as a matrix and carbon nanotubes (CNTs) as reinforcing additives were fabricated by high-temperature and high-pressure sintering (HTHP). Microstructures, mechanical properties, fracture modes and toughening mechanisms of these composites were investigated. Composites exhibited excellent bending strength, wear resistance, and fracture toughness. Fracture toughness of composites reached 7.02 MPa·m1/2. Comparing to pure cBN matrix, bending strength improved from 475.27 to 600.15 MPa, and wear resistance increased by 43.23%. Such improvements of mechanical properties were mainly attributed to pullout and bridging reinforcements by CNTs. CNTs incorporation also changed fracture mode from inter-to trans-granular. Image 1 [ABSTRACT FROM AUTHOR]