微晶云母陶瓷微型拉瓦尔喷管的超声加工关键技术

Critical techniques of ultrasonic machining for micro Laval-nozzles of microcrystalline-mica-ceramics

将微细超声加工方法与微细电火花加工方法相结合,解决了微晶云母陶瓷的微型拉瓦尔喷管加工中的关键技术问题,其中包括高精度多功能特种加工系统、微细超声工具的制备、工件的装夹与定位、超声加工工艺流程的设计及超声加工参数的选择。在自行研制的高精度多功能加工系统上,采用微细超声加工方法加工微晶云母陶瓷微型拉瓦尔喷管,采用微细电火花加工方法制备相应的超声加工工具,并且设计了工件夹持装置,将重复定位精度控制在2μm以内。此外,通过2套工艺流程方案的加工对比实验,选择出较优的加工方案,成功加工出入口直径为360μm、出口直径为320μm、喉部直径为170μm、总长为550μm的拉瓦尔喷管。

Micro-ultrasonic-machining（micro-USM） and micro electrical discharge machining（micro-EDM） were jointly used to resolve the critical problems of micro Laval-nozzle machining techniques of microcrystalline-mica-ceramic（MCMC）,including a special machine with high precisions and multiple functions,the preparation of micro-USM tools,the clamping and locating of workpieces,the design of micro-USM process and the selection of the micro-USM conditions.Though a self-developed high-precision multi-functional machine tool,micro-USM was adopted to machine micro Laval-nozzles of MCMC cooperated with micro-EDM for tools preparation.Workpiece holding devices were designed to keep the repeat positioning accuracy less than 2 μm.Furthermore,by comparing two machining processes,a Laval-nozzle was successfully made by the better machining process with an inlet diameter of 360 μm,outlet diameter of 320 μm,throat diameter of 170 μm and total length of 550 μm.