Search

In order to improve the wear resistance of aluminum matrix composites and reduce the cost at the same time, the Al2O3/Al composite powder was prepared by hydrothermal method in this experiment, and the material properties of the Al2O3/Al metal matrix composite powder material were studied. It can be seen from the results that the encapsulation degree of Al2O3/Al-based composite powder material first increases and then decreases with the increase of ammonia concentration, and first increases and then decreases with the increase of PH value. The optimal molar ratio of salt and alkali is 1:1. Through the optimization of process parameters, the ratio of aluminum nitrate and ammonia water is obtained as: 1:1, the slurry stirring speed is 1500r/min, the stirring time is 10min, and the heating temperature is 200°C, the obtained composite powder is relatively uniform, has a larger specific surface area, and has better powder properties.

On the one hand, cermet has the advantages of metal materials, and on the other hand, it maintains the excellent properties of ceramic materials, and is a very important new engineering material. In this paper, the alumina/aluminum cermet material composite powder was prepared by ball milling, and its densification properties were characterized and studied to provide reference for the preparation of high-performance cermet materials. When the ball milling time is more than 6h, the distribution of alumina particles around the aluminum powder is relatively uniform. The research shows that: with the extension of the ball milling time, the number of pinning of Al2O3 particles on the surface of the Al ball first increases and then decreases; The trend of decreasing; with the increase of ball-to-powder ratio, the distribution of Al2O3 particles on the surface of Al balls is more uniform. Considering its cost-effectiveness, it is more suitable to prepare pinned alumina/aluminum-ceramic composite powder under the conditions of ball milling speed of 360r/min, ball-to-material ratio of 2:1 and ball milling time of 12h. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When the Al content gradually decreased, the density and hardness of the cermet material also decreased gradually. When Al accounts for 75% in the sample, the microstructure is dense and the hardness is higher. When the molding pressure is 20MPa, the unevenness of the surface of the material is greatly relieved, relatively flat, and the densification effect is better. When the sintering temperature is 800°C, the fired sample is very dense, and the particles have relatively high bonding strength, but a small amount of aluminum is precipitated on the surface of the sample, forming a silver-white spherical substance.

With the popularization of electricity, the use of electric porcelain is becoming more and more extensive, but in the process of production, the waste of electric porcelain continues to accumulate and increase, which not only pollutes the environment but also affects the normal life of human beings. Therefore, it is urgent to deal with these electric porcelain wastes. In this paper, the electric ceramic waste is used as the main raw material, and starch and kaolin are added to optimize the formula to prepare porous ceramsite. The effects of the content of electrical ceramic waste, sintering temperature and holding time on the properties of porous ceramsite were studied. After research, the results show that with the increase of waste content, the porosity and water absorption first decrease and then increase, while the compressive strength first increases and then decreases. With the increase of the sintering temperature, the porosity and the water absorption rate decrease continuously at the beginning, and the compressive strength increases continuously at the beginning, but when the sintering temperature increases continuously, there will be a turning point or a flattening point. With the continuous extension of the holding time, the water absorption and porosity continue to increase, while the compressive strength continues to decrease, but the overall change is small. The optimization can be found that when the waste content is 75%, the sintering temperature is 1200 °C, and the holding time is 30 min, the prepared porous ceramsite has the best performance. Its water absorption rate: 13.87%, porosity: 27.52%, compressive strength: 20.06MPa.

With the popularization of "sponge city" in the whole country, the use of permeable bricks is increasing every year. Although the raw materials required for the preparation of permeable bricks are widely sourced, there are few reports on the process of using refractory waste to prepare permeable bricks. It is the ball milling process of refractory waste. The effects of ball milling time, ball mill rotation speed, and ball-to-material ratio on the properties of refractory waste were mainly studied. Through the experimental results and analysis, the following conclusions can be drawn: with the increase of ball milling time, ball milling speed and ball-to-material ratio, the particle size of refractory waste powder gradually decreases. Through research, it is concluded that the optimal ball milling time is 4h, the ball milling speed is 100r/min, and the ball-to-material ratio is 2:1.

In view of the low performance of porous ceramics on the wall, the heavy task of saving clay resources, and the major problems of dredging the Yangtze River, this thesis uses low-grade quartz sand along the Yangtze River as the main raw material and kaolin as the plasticizer. Drying, sintering and other processes prepare high-performance porous quartz ceramics, and improve the performance of porous quartz ceramics by studying the control conditions and the control mechanism related to the performance of the sintered body. Quartz porous ceramic bodies were sintered at 1100 °C and 1200 °C, and no obvious gradient structure was found. However, the quartz porous ceramic bodies had obvious gradient structures after sintering at 1300°C. The quartz porous ceramic bodies were sintered. When the temperature is 1400 °C, the green body is not found to have a pore gradient structure. When the water-to-material ratio is 1.2 and 1.3, the quartz porous ceramic body has no obvious gradient structure; when the water-to-material ratio is 1.4, 1.5, the sample has an obvious gradient structure. Combining the cost performance between material performance and energy consumption, in order to obtain a better bonding point, porous silica ceramics should be prepared with a water-to-material ratio of 1.4 and a sintering temperature of 1300 °C to prepare porous silica ceramics with a better pore gradient structure. Its porosity is 32.45%, and its compressive strength is 5.23 MPa.

As a kind of sponge city water-permeable material, permeable brick has good water permeability, chemical stability, corrosion resistance and weather resistance. Therefore, the development of permeable brick also broadens the engineering application market for its application. The discharge of a large amount of manganese slag will cause serious environmental pollution, and the problem of manganese tailings accumulation is serious. There is no ideal treatment method at present. In this paper, manganese tailings slag is used as the main raw material to prepare sponge city permeable bricks, thereby turning waste into treasure. Through research, the permeable brick with MgO used as sintering aid has very low compressive strength and good water permeability. CaO used as a sintering aid has high compressive strength and low water permeability. The porosity and water permeability of permeable bricks increase with the increase of CaCO3, but the compressive strength is opposite. In comparison, the permeable bricks prepared with three different sintering aids, 3% CaCO3 and 2% MgO as sintering aids have good water permeability and superior compressive strength. The permeability coefficient of the permeable brick prepared with 3%CaCO3 and 2%MgO as sintering aids is 2.0×10-2cm/s, and the compressive strength is 1.3MPa.

In this paper, the YAG powder is prepared by the co-precipitation method. In addition, the sintering aid to aid sintering and the high temperature foaming agent that becomes gas released during the heating process so that the sample has pores, the ball mill mixes the material, and the sample press is extruded. Box-type resistance furnace sintering. Through this process, porous ceramics can be made. Study the effect of sintering aid content, foaming agent type, sintering temperature on the properties of YAG porous materials. The analysis and discussion can lead to the following conclusions: as the content of sintering aid silica in the sample increases, the sintering temperature of the sample decreases. It is best when the ratio of sintering aid alumina to silica is 3:1. The moldability of the sample whose foaming agent is wood chips is worse than that of the sample whose foaming agent is fiber and carbon powder. The ratio of sintering aid alumina to silica is 3:1, and the sintering temperature of the sample with carbon powder as the blowing agent is best when the sintering temperature is 1400 °C.