Carbon fiber reinforced silicon carbide composite materials (Cf/SiC) have become the core material of hot end components of aircraft engines due to their high temperature resistance and high strength. However, an aviation manufacturing company encountered severe challenges when processing Cf/SiC combustion chamber components: it was necessary to complete 0.2mm diameter deep holes, M3 threaded holes and high-precision plane milling on a workpiece with a thickness of 15.5mm, and the traditional process was completely ineffective.
Processing products
Material: Carbon fiber reinforced silicon carbide composite materials (Cf/SiC)
Processing features:
1.ɸ0.2mm deep hole processing (depth 15.5mm)
2.M3 threaded hole precision forming
3.High-precision plane milling
Processing background and difficulties
A. Processing background
Cf/SiC composite materials are widely used in aircraft engine combustion chambers and rocket nozzles due to their high temperature resistance (＞1600℃) and lightweight characteristics. However, its hardness (Rockwell 90HRA) and brittleness make it difficult for traditional processing technology to achieve mass production of micro holes and threads.
B. Difficulties of traditional processing solutions
1. The breakage rate of traditional carbide drills when processing ɸ0.2mm holes exceeds 90%
2. EDM produces a 50μm ablation layer, causing the components to fail under high temperature conditions
3.The coaxiality deviation of M3 threaded holes is > 0.03mm, which cannot meet the AS9100D standard
BISHEN Solutions
By integrating ultrasonic vibration and super-hard tool technology, we provide a full-link processing solution:
Ultrasonic green and efficient precision engraving and milling center: 20kHz high-frequency vibration system
Customized PCD tool set:
0.2mm overall PCD micro-drill (length-to-diameter ratio 77:1)
3-edge PCD thread milling cutter (helix angle optimization design)
Nano-edge PCD flat milling cutter
Intelligent process parameter library: axial cutting force control ≤5N, speed 30,000rpm
Processing advantages
Ultrasonic + PCD micro-drilling achieves heat-free processing, hole wall roughness Ra3.2μm (36% higher than EDM)
M3 threaded hole coaxiality <0.01mm, 100% passed three-coordinate detection
The life of a single PCD tool is up to 300 holes, and the processing efficiency is increased by 4.2 times
Processing comparison
D0.2 hole enlarge picture
About MID
MID (Mid Precision) is a solution provider focusing on the manufacturing of high-precision metal parts. Its 7,500 square meters of intelligent factory is equipped with advanced technology clusters such as ultrasonic assisted processing. The company has been deeply involved in the fields of aerospace, medical equipment and robotics, especially in the field of micro-hole processing of difficult-to-cut materials such as carbon fiber composite materials and high-temperature alloys. Through the integrated service model of "ultrasonic precision machining + super-hard tool customization", it has successfully supported the mass production of Cf/SiC structural parts for multiple types of aircraft engines, and the relevant technology has passed the AS9001 aerospace quality management system certification and the medical ISO 13485 certification.
