What is rapid annealing What is the process flow of rapid annealing
When smelting metal, annealing is performed, which is an indispensable process, and its purpose is to increase the toughness of the metal. Next, Kehua will take a look at what is rapid annealing, and what is the process flow of rapid annealing? The sample is heated to about 700~1200℃ to complete the annealing in a few seconds~tens of seconds. Compared with conventional thermal annealing, it has the following advantages: the sample can use a higher annealing temperature under the same protection conditions, which is beneficial to improve the activation rate and mobility of implanted impurities, especially suitable for large-dose implanted samples, because The damage caused by high-dose implantation is serious, and it needs to be annealed at a higher temperature. Transient annealing can reduce the redistribution of implanted impurities and form a steep impurity distribution or abrupt junction. In addition, when the annealing temperature is not very high, the surface of the sample does not need to be used. Dielectric film protection simplifies the process. Rapid annealing What is the process flow of rapid annealing? 1. A bismuth-aluminum composite inoculant is used, so low temperature inoculation is carried out to increase the graphite core. 2. The furnace temperature of the original graphitization process in the first stage is uneven, some castings are overheated for a long time, and the number of graphite cores is reduced, which affects the decomposition of the graphitized pearlite in the second stage. The new process heats up at a relatively fast rate after inoculation at low temperature. When the temperature reaches 750~850℃, the temperature difference at each point in the furnace is controlled to be 50~60℃, so that all castings can reach high temperature at the same time, and the temperature is maintained at 960~980℃. It is necessary to strictly control the temperature difference in the furnace at about 20 °C to prevent local overcooking. 3. In order to reduce the annealing time, after the first stage of graphitization, the temperature is lowered to 760°C by air blowing, and then cooled to 720°C at a rate of 10°C/hour. After 4 hours, the furnace is stopped and cooled to 680°C. Kehua believes that due to the good graphitization in the low temperature incubation stage and the first stage, the graphitization time in the second stage is shortened to 4 hours. Rapid annealing is a relatively advanced annealing technology that has been widely used. After the metal is rapidly annealed, the toughness can be greatly increased or decreased.