Effect of heat treatment and use of materials testing technology

1, 1) main technical requirements of heat treatment equipment Because of the aluminum alloy quenching and aging temperature range is small ( Because of the quenching temperature is close to in low melting point alloy melting point of eutectic composition) , so the difference in temperature inside the furnace should be controlled in + / - 5 ℃; 2) For temperature measurement, the instrument control is sensitive, accurate, to ensure the temperature within the error range; 3) District of temperature in the furnace should be uniform, the difference in 1 - 2 ℃ range; 4) Quenching tank has a heating device and circulation system, to ensure uniform heating and temperature of the water; 5) Should regularly check and replace the contaminated water. 2, is to ensure that the implementation of quenching medium quenching medium heat treatment purpose or function of the most important factors. The higher the cooling speed of quenching medium, the casting cooling of more intense, Fast) , the metal in the organization of alpha solid solution, the higher the degree of supersaturation, the mechanical properties of castings is, the better, because a lot of intermetallic compounds, such as strengthening phase by solid solution into the alpha solid solution of Al. Quenching medium according to the order of the cooling rate of castings and speed is: a mixture of dry ice and acetone ( - 68℃） , ice water, room temperature water, 80 - 90 ℃, 100 ℃ water, the water atomized water, all kinds of oil ( Rapeseed oil, etc. ) And heated to 200 - 220 ℃ of all kinds of oil, air, etc. In recent years, domestic CL - developed aluminium alloy quenching medium 1 cooling rate between oil and water, it can be any miscibility with water ratio, its blending ratio is different, different cooling rate, therefore, very easy to adjust the cooling speed according to quenching objects. It needn't to wash after quenching and the surface is bright and clean, no pollution, non-toxic finish for the castings, and they're rustproof. Is the main technical indexes, appearance: light yellow to yellow sticky and homogeneous liquid, density: 1. 085 - 1. 1234 mg / ㎡, viscosity Y38: p 154 mpa & # 8226; S, inverse melting point: 80 87 ℃, refraction n: 1. 4138 - 1. Critical cooling rate: 4450, 260 ℃ / s (or higher 450 - 260℃） 。 CL- 1 organic hardening agent hardening characteristics of aqueous solution are excellent, its mechanism is the solution in the quenching process of workpiece, can be in the temperature rises to a certain value, the precipitation in aqueous solution, organic composition and decomposition, and on the surface of workpiece formed a uniform layer of conductive film, quenching air bubbles is a direct effect on the film to artifacts, rather than a direct effect on workpiece, which reduces the formation of quenching stress direct tapping effect, and thus reduce the workpiece deformation and crack, and after quenching, the cooling water solution to a certain temperature, the organic film and dissolved in aqueous solution, uniform back to the original state of aqueous solution, does not interfere with repeated use effect. 3, temperature measurement, temperature control table and material temperature measurement, the precision of temperature control table should not be lower than 0. Level 5, heat treatment furnace of the warm temperature control should be equipped with automatic test automatic recording, automatic alarm, automatic power, wired devices and instruments, to guarantee the accuracy of the furnace temperature display and control, and uniform temperature. Thermocouple with nickel and chromium - Nickel, nickel chromium - silicon The diameter of the nickel aluminum was 2. 0 - 0. 5 ㎜ accidentally silk. To improve the sensitivity of temperature meter, narrow temperature range, it is best to use Ф 0. 5 - 1. 0 ㎜ accidentally silk material above. And before use and use of the process ( 1) every 3 months 1 testing and calibration.