Effect of sintering process on microstructure and magnetic properties of high frequency power ferrite

An oxide ceramic process was adopted to prepare high frequency manganese-zinc (MnZn) power ferrite. In combination with the microstructure analysis of material, the influences of sintering process on initial permeability (μi) and high frequency loss in unit volume (Pcv) of MnZn power ferrite were investigated. The results show that in order to obtain fine microstructure and high frequency properties, the preferable sintering temperature and atmosphere are 1230 ℃ and oxygen partial pressure ( PO2) of 4%, respectively.     

Study on sintering process and characteristic of nanosized soft magnetic MnZn ferrite powders

The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sample of MnZn ferrite was prepared by both traditional pressing and cool isostatic pressing on MnZn ferrite nanoparticals. The sintering process of which was segmented. Thedensity, microstructure and phase composition of sintered sample were analyzed by Archimedes'law, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain growth and densification in sintering process of MnZn ferrite were investigated. The magnetic property was measured by vibrating sample magnetometer (VSM) and Nim2000 magnetic material testing system. The results show that the better sintering temperature is 850 ℃, at which the better magnetic property and microstructure of sintered compact were obtained.     

中频炉酸性炉衬使用寿命的探讨

通过对炉衬材料的选择,作用机理及影响石英砂炉衬材料寿命的相关因素的阐述,说明了SD-T-A石英砂干振料可提高中频炉酸性炉衬使用寿命的原因.     

纳米W-Cu粉末的均相沉淀法制备及其烧结性能

采用湿化学工艺--蒸氨均相沉淀法,制备了纳米CuWO4·2H2O/Cu2WO4(OH)2均相沉淀物,然后煅烧、还原,得到含Cu 30%的W-Cu复合粉.将该复合粉压坯在H2气氛中于不同温度下烧结后,对烧结体的微结构和物理、力学性能等进行了测试分析.实验结果表明:蒸氨均相沉淀法制备的W-Cu复合粉体具有纳米粒度和均匀的化学组成,其烧结活性高,在较低温度下烧结即可达很高的致密化程度.由上述W-Cu粉体所制备的烧结体具有良好的物理、力学性能.     

活性石灰/粉煤灰制备烧结烟气脱硫剂配比试验研究

本文研究了以钢铁企业常用物料活性石灰和自备电厂粉煤灰制备的脱硫剂,在循环流化床脱硫试验装置上进行了烧结烟气脱硫剂配比试验.试验结果表明,活性石灰与粉煤灰的质量比按1:2配置时,脱硫剂钙的利用率较高,具有较好的经济性.     

MIM Fe基合金的合金化强化

研究金属粉末注射成形铁基合金在强还原性氢气氛烧结条件下的合金化强化效果，结果表明，添加Ｃｕ、Ｎｉ、Ｍｏ等元素能取得显著的固溶强化效果，其中成分为Ｆｅ－２Ｎｉ－２Ｃｕ－０．４５Ｍｏ的机械性能达到σｂ＝４８３ＭＰａ，σｓ＝３４０ＭＰａ，δ＝９％和ＨＲＢ８３。     

Microstructures and properties of coating from cemented carbide by vacuum powder sintering

In this paper, the microstructures and properties of coating from cemented carbide of WC–Fe–Co–Ni on the substrate 45 steel are studied. The effects of sintering temperature on the microstructures of coating, the interface structures between coating and the substrate, the microhardness distribution and its wear resistance in the coating are investigated. The results indicate that the coating is strongly metallurgical bonded with the substrate by the mutual diffusion and penetration of Fe towards the coating and W, Co, Ni towards the substrate at sintering temperature ranging from 1280 °C to 1300 °C. The coating obtained exhibits compact structure and uniformly distribution of WC with fine grain and porosity free from defects, having high microhardness and preferable wear resistance.     

Laser-Sintered Barium Titanate

Laser sintering of alkoxy-derived ultrafine BaTiO₃ powders was investigated. The temperature increases of the sample with laser irradiation were measured with a thermocouple. It was found that laser irradiation could generate enough heat to sinter ceramics. A slurry was prepared by mixing an alkoxy-derived BaTiO₃ powder, binder additives, solvent, and plasticizer. The slurry was tape cast and dried to give a green sheet. The green sheet was laser sintered and was then characterized by SEM, XRD, and density measurements. The effect of burnout before laser irradiation and the characteristic microstructure of laser-sintered BaTiO₃ are described.     

Kinetics of the Initial Stage of Sintering from Shrinkage Data: Simultaneous Determination of Activation Energy and Kinetic Model from a Single Nonisothermal Experiment

A new method for the kinetic analysis of the initial stage of sintering for constant-heating-rate data has been proposed. Unlike all of the methods previously reported in the literature, this new method proposed here allows the simultaneous determination of the activation energy and the kinetic model from a single dilatometric curve recorded under a linear-heating-rate program. The proposed method has been tested with simulated sintering curves and experimental results have been obtained for the sintering of a rutile sample.     

Rapid Reactive Synthesis and Sintering of Submicron TiC/SiC Composites through Spark Plasma Sintering

Submicrometer TiC/SiC composites were fabricated by a rapid reactive sintering process through spark plasma sintering (SPS) technique using the carbon, titanium, and nanosized-SiC powders without any additive. It was found that the composite could be sintered in a relatively short time (8 min at 1480°C) to 97.9% of theoretical density. After sintering, the phase constituents and microstructures of the samples were analyzed by X-ray diffraction techniques and observed by scanning electron microscopy. The effect of nanosized and microsized SiC additives on the microstructure of TiC/SiC composites was investigated.