低温磨料气射流加工装置的研制与实验验证

针对磨料气射流加工技术在常温下无法加工聚二甲基硅氧(Polydimethylsiloxane,PDMS)等聚合物材料的问题,提出了低温磨料气射流加工PDMS等聚合物材料的设想。设计了一套低温磨料气射流加工装置,通过改变浸没在液氮中的蛇形管长度,可以得到不同温度的低温磨料气射流。建立了蛇形管长度计算的数学模型,通过实验验证了该模型的可行性,为以后对低温磨料气射流加工进行更深入的研究奠定了基础。用不同温度的磨料气射流加工PDMS,发现常温下磨料气射流无法加工PDMS,而低温下可以进行加工。低温下加工PDMS可以提高孔的横截面质量,材料去除机理为塑性去除和脆性去除的结合。

Development of Cryogenic Abrasive Air Jet Machining Equipment with Experimental Verification

Aiming at the problem that polydimethylsiloxane (PDMS) and other polymer materials cannot be machined by abrasive air jet at normal temperature, an idea of machining PDMS and other polymer materials by cryogenic abrasive air jet is put forward. A cryogenic abrasive air jet machining device is designed. Cryogenic abrasive air jet at different temperatures can be obtained by changing the length of serpentine tube immersed in liquid nitrogen. A mathematical model for calculating the length of serpentine tube is established, and the feasibility of the model is verified through experiments, which provides a solid foundation for further research on cryogenic abrasive air jet machining. PDMS are machined by abrasive air jet at different temperatures and it is found that abrasive air jet machining for PDMS targets is impossible at room temperature while cryogenic abrasive air jet machining allows the drilling of holes. The cross section qualities of holes machined at low temperature can be improved. The material removal mechanism of cryogenic abrasive air jet machining of PDMS is the combination of ductile erosive and brittle erosive systems.