Cooling Curve Analysis of A356 Alloy by Conventional Casting and the Effect of Stirring

The present investigation attempted to explore the effect of stirring during solidification of Aluminum A356 alloy, mainly focusing on the change from dendrite to globular structure. For this purpose samples of A356 alloy were melted in the electrical resistance furnace and cooling curves were recorded for each level agitation. The experimental curves were numerically processed by calculating first and second derivatives. From these were determined temperatures and times of start nucleation of alpha solid and eutectic reaction.

Influence of Different Heater Structures on the Temperature Field of AlN Crystal Growth by Resistance Heating

Based on the actual hot zone structure of an AlN crystal growth resistance furnace, the global numerical simulation on the heat transfer process in the AlN crystal growth was performed. The influence of different heater structures on the growth of AlN crystals was investigated. It was found that the top heater can effectively reduce the axial temperature gradient, and the side heater 2 has a similar effect on the axial gradient, but the effect feedback is slightly weaker. The axial temperature gradient tends to increase when the bottom heater is added to the furnace, and the adjustable range of the axial temperature gradient of the side 1 heater + bottom heater mode is the largest. Our work will provide important reference values for AlN crystal growth by the resistance method.

Research on edge controller based on industrial furnace

Traditional control instruments and DCS control systems are limited by shortcomings such as single control function, independent controlled elements, inability to close-loop control on site, and ineffective communication. Aiming at these problems, this paper proposes a kind of industrial furnace edge controller which has the functions of acquisition, calculation, control, storage, output and communication in one. The edge controller structure, edge computing and the control method applied to edge computing are designed. The fuzzy PID control method is compared with the conventional PID control method by taking the temperature control of resistance furnace as an example. The simulation shows that the control effect of fuzzy PID on resistance furnace temperature is obviously better than that of conventional PID. The test results also show that the performance indices for the fuzzy PID control are better, which again proves that the fuzzy PID control outperforms. The research results of this paper are of reference value for engineering applications.

Study of Controlled Aluminum-Vanadium Alloy Prepared by Vacuum Resistance Furnace

In this paper, V2O3 is used as the raw material, and an Al-V alloy is synthesized by vacuum resistance furnace heating. The results show that with the extension of the heating time, the separation effect of the alloy and the slag and the uniformity of the alloy are significantly improved. The slag is fully separated from the alloy, and the composition of the alloy is more uniformly distributed when the heating time is controlled at 1 hour. In addition, the composition of the alloy is affected by increasing content of Al. In particular, the obtained alloy composition meets commercial standards when the mass ratio of Al is 31-36 wt%. The effect of different mass ratios of CaO on the quality of slag series and alloys was also investigated. The results show that the composition distribution of the slag system can be effectively changed with increasing the mass ratio of CaO, and the uniformity of the alloy composition is also optimized. When the mass ratio of CaO is 27 wt%, the alloy and slag are well separated, and the composition distribution in the obtained alloy is more uniform. In addition, the content of impurities in the alloy can be effectively improved under vacuum. Therefore, it is suggested that a vacuum resistance furnace should be applied in the industrial production of high-quality Al-V alloy.

Factors influencing dissolution of carbonaceous materials in liquid Fe–Mn

Carbon dissolution from four types of metallurgical cokes and graphite was investigated by using immersion rods in a resistance furnace to clarify the influence of factors governing the rate of carbon dissolution from carbonaceous materials into Fe–Mn melts at 1550 °C. The factors studied were the microstructure of carbonaceous materials, roughness, porosity and the wettability between carbonaceous materials and the melt. Carbon/metal interface was characterised by scanning electron microscopy accompanied with energy-dispersive X-ray spectrometry to investigate the formation of an ash layer. The results showed that coke E had the highest dissolution rate. Surface roughness and porosity of the carbonaceous materials seemed to be dominant factors affecting the dissolution rates. Further, crystallite size did not have a significant effect on the dissolution rates. Solid/liquid wettability seemed to affect the initial stage of dissolution reaction. The dissolution mechanism was found to be both mass transfer and interfacial reactions.