Atmosphere control method of forming cavity of slm equipment

Abstract

The atmosphere control method of the SLM equipment forming chamber of the present invention includes a cycle start step, an intake and exhaust cycle start step and a stop cycle step. The cycle start step includes the first vacuum pumping and the second vacuum pumping twice. The cycle start step includes, when the oxygen content is greater than the set value, performing exhaust for time t2, and then performing intake air for time t3, and the cycle stop step is performed between the cycle start step and the intake and exhaust cycle start step After any step is executed, the stopped step is executed when the cycle needs to be closed. This control method does not require high airtightness of the forming cavity, does not waste a lot of gas, has good stability, and is more convenient for debugging and maintenance.

Description

technical field [0001] The invention relates to the field of metal melting additive manufacturing, in particular to an atmosphere control method for a forming chamber of an SLM equipment. Background technique [0002] One of the necessary working conditions for SLM equipment (also known as metal melting additive manufacturing equipment) is that the oxygen content of the forming cavity is required to be lower than 0.1%, otherwise it will affect the printing quality. When printing titanium alloys, aluminum alloys, etc. Metals can even lead to failure to print successfully, and what's more, it can cause an explosion. Therefore, a difficult point and key technology in the development of SLM equipment is the design of the forming cavity and the control of the atmosphere circulation of the forming cavity. [0003] The control methods of SLM setting cavity atmosphere circulation mainly include direct replacement gas method and vacuum pumping + intake and exhaust cycle control meth...

AI Technical Summary

Problems solved by technology

The problem with the negative pressure replacement gas method is that it needs to be realized by continuously turning on / off the vacuum pump, which will cause certain damage to the vacuum pump and cause serious heat generation when the vacuum pump runs for a long time. If the heat dissipation is not good enough It is easy to burn out the motor, which will affect the service life of the vacuum pump; on the other hand, the vacuum pump adopts a negative pressure control method, which requires high air tightness of the cavity, and the oxygen content in the cavity is difficult to maintain for a long time. Maintain, control stability is difficult to be guaranteed

In addition, this negative pressure displacement gas method also has the problem of consuming a large amount of gas

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