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Novel silica bricks were made of crystalline silica with ferrosilicon nitride as the mineralizer. The phase, microstructure, pore characteristics and high-temperature properties of the novel silica bricks prepared by adding 1%, 1.5% and 2% ferrosilicon nitride were characterized. The results showed that, compared to conventional silica bricks (with mineralizers of calcium hydroxide and iron scale), the novel silica bricks with the addition of ferrosilicon nitride contained less calcium oxide, less residual quartz and more tridymite. The ferrosilicon nitride was gradually oxidized to form SiO 2 and Fe 2 SiO 4 during the firing stage of the silica bricks. After adding ferrosilicon nitride, the degree of particle breakage was reduced, and the pore size of interconnected pores increased. With the increase in ferrosilicon nitride content, the silica brick structure gradually densified. The silica brick sample with 2% ferrosilicon nitride achieved better creep resistance at high temperature (1550 °C, 0.2 MPa), but the refractoriness under load of the bricks was slightly reduced by using ferrosilicon nitride as a mineralizer. An optimization model of ferrosilicon nitride as a mineralizer was established. [ABSTRACT FROM AUTHOR]

Silica refractory has excellent high-temperature performance, but its apparent porosity is relatively high. In this work, samples obtained before and after creep testing of silica brick (1550 °C, 50 h), from used silica checker brick (existing only tridymite and amorphous) and from used dome brick (existing only cristobalite and amorphous) were investigated using a three-dimensional structure model based on X-ray computed tomography (CT). The results show that the porosity of silica brick was high but consisted mainly of interconnected pores, with a very small proportion of closed pores (smaller after long-term use). During the use of silica brick, the morphology and phase transformation caused large particles to rupture, and the mineralizer became liquid at high temperature. The broken particles and interconnected pores provided channels for the migration of the liquid in the brick at high temperature. The silica brick presented a homogeneous ceramic structure during long-term operation. Tridymite or cristobalite presented a solid frame leading to an excellent creep performance of the silica brick (the creep rate of the checker brick was −0.16% at 1550 °C for 50 h). Results were discussed, compared with literature and a model for the transformation of the silica brick from a refractory structure to a homogeneous ceramic structure was established in this paper. [ABSTRACT FROM AUTHOR]

The sagger, primarily composed of aluminum-silicon, serves as an essential vessel in the sintering process of ternary lithium battery anode materials (LiNi x Co y Mn 1-x-y O 2 , LNCM). However, the acidic oxide SiO 2 in the sagger material readily reacts with Li 2 O in the cathode material, forming substances such as LiAlO 2 or LiAlSiO 4 , resulting in volume expansion, which makes the sagger spalled and damaged. In this study, β-Al 2 O 3 –MgAl 2 O 4 multiphase materials with excellent alkali resistance were prepared using the high-temperature solid-state method. The effects of anhydrous sodium carbonate content and heat treatment temperature on the properties of the composites were investigated, and the thermal shock resistance of the specimens was evaluated by the water-rapid-cooling method, as well as the LNCM corrosion resistance of the specimens was evaluated by the static crucible method. The results showed that the overall performance of the specimens was the best at a anhydrous sodium carbonate content of 6 wt%, with a compressive strength of 57.50 MPa and a flexural strength of 42.49 MPa after firing at 1600 °C for 4 h. The strength retention of the specimens was 33.21 % after one thermal shock at a thermal shock temperature of 900 °C. The specimens showed excellent resistance to erosion as there were no obvious erosion traces on the surface of the specimens after undergoing five cycles of erosion. [ABSTRACT FROM AUTHOR]

This paper presents a high-efficiency boost converter with a wide input range and a start-up strategy of sharing main power NMOS which can start-up at an input voltage of 700 mV. A burst mode with boundary conduction mode (BMBCM) control is utilized in the proposed boost converter to achieve high efficiency across the wide input power range. A method is also suggested to determine the optimal peak inductor current for a given input range. Compared to other start-up strategies, the proposed start-up circuit reduces chip area by sharing the main power NMOS with the normal operation mode, eliminating the need for an additional start-up power transistor. A new ultra-low-power voltage detection circuit is used to control the start-up process. The proposed boost converter is designed and fabricated in a 180 nm BCD process with an active chip area of only 0.33 mm2. The circuit achieves a peak efficiency of 94.8% at an input voltage of 3 V and an output voltage of 3.6 V, while maintaining an efficiency of at least 65.9% across the input power range of 7 μW to 300 mW. [ABSTRACT FROM AUTHOR]