CN-121988915-A - Ultra-fast laser processing method for special-shaped air film hole of ceramic matrix composite material

CN121988915ACN 121988915 ACN121988915 ACN 121988915ACN-121988915-A

Abstract

A processing method using ultrafast laser is used for processing a special-shaped air film hole of a ceramic matrix composite material. The machining method comprises the steps of S1, S2, S3 and S4, wherein the step S1 is used for carrying out rotary cutting rough machining on an entity by using ultra-fast laser pulses to obtain a through first rough machining straight round hole, the step S2 is used for carrying out layered milling rough machining on the entity on the outer peripheral side of the partial depth of the first rough machining straight round hole by using ultra-fast laser pulses to obtain a rough machining abnormal-shaped hole and a second rough machining straight round hole which are communicated with each other, the step S3 is used for carrying out layered milling finish machining on the wall body of the rough machining abnormal-shaped hole by using ultra-fast laser pulses to obtain a finish machining abnormal-shaped hole, the finish machining abnormal-shaped hole is communicated with the second rough machining straight round hole, and the step S4 is used for carrying out rotary cutting finish machining on the wall body of the second rough machining straight round hole by using ultra-fast laser pulses to obtain a finish machining straight round hole, and the finish machining straight round hole is communicated with the finish machining abnormal-shaped hole.

Inventors

ZHOU SONGHUA
WANG GONGGUAN
ZHAO HONGQING
GAO YIBO
ZHANG YAN
WU SHIZHI

Assignees

中国航发商用航空发动机有限责任公司

Dates

Publication Date: 20260508
Application Date: 20241104

Claims (9)

1. The ultra-fast laser processing method for the special-shaped air film hole of the ceramic matrix composite material is characterized by comprising the following steps of: S1, carrying out rotary cutting rough machining on an entity by using ultra-fast laser pulses to obtain a through first rough machining straight round hole; s2, carrying out layered milling rough machining on the entity on the outer peripheral side of the partial depth of the first rough machining straight round hole by using ultra-fast laser pulses to obtain a rough machining special-shaped hole and a second rough machining straight round hole which are communicated with each other; s3, carrying out layered milling finish machining on the wall body of the rough machining special-shaped hole by using ultra-fast laser pulse to obtain a finish machining special-shaped hole, wherein the finish machining special-shaped hole is communicated with the second rough machining straight round hole, and S4, carrying out rotary cutting finish machining on the wall body of the second rough machining straight round hole by using ultra-fast laser pulses to obtain a finish machining straight round hole, wherein the finish machining straight round hole is communicated with the finish machining special-shaped hole.
2. The processing method according to claim 1, characterized in that: the diameter of the first rough machining straight round hole is 60% -80% of the diameter of the finish machining straight round hole.
3. The processing method according to claim 2, characterized in that: The diameter of the first rough machining straight round hole is 0.4 millimeter, and the diameter of the finish machining straight round hole is 0.6 millimeter.
4. The processing method according to claim 1, characterized in that: The cross section size of the material removed by the layered milling finish machining is 10% -20% of the depth of the finish machining special-shaped hole.
5. The method of claim 4, wherein: the cross-sectional dimension of the material removed by the layered milling finish is 0.1 mm, and the depth of the finish profiled hole is 0.8 mm.
6. The processing method according to claim 1, characterized in that: The single-layer feed depth of both the layered milling finish and the layered milling rough was 0.01 mm.
7. The processing method according to claim 1, characterized in that: The energy intensity of the ultrafast laser pulses of the step S3 and the step S4 is smaller than the energy intensity of the ultrafast laser pulses of the step S1 and the step S2.
8. The processing method according to claim 7, characterized in that: the energy intensity of the ultrafast laser pulses in the step S3 and the step S4 is 40% -60% of the energy intensity of the ultrafast laser pulses in the step S1 and the step S2.
9. The processing method according to claim 8, characterized in that: the average power of the ultrafast laser pulses of the step S3 and the step S4 is ten watts, and the average power of the ultrafast laser pulses of the step S1 and the step S2 is twenty watts.

Description

Ultra-fast laser processing method for special-shaped air film hole of ceramic matrix composite material Technical Field The invention relates to material removal processing of ceramic matrix composite materials, in particular to an ultrafast laser processing method for a special-shaped air film hole of a ceramic matrix composite material. Background Commercial aviation turbofan engine drives turbine rotation through compressed air combustion acting and produces thrust. With the continuous improvement of the thrust performance requirements of the aircraft, the high-temperature resistance of hot end components such as a high-pressure turbine and the like in the development process of the commercial aircraft engine is very difficult, and the adoption of a high-performance composite material process and an advanced structural design method is one of the potential ways. In recent years, development and application of ceramic matrix composites (Ceramic Matrix Composite, CMC) have attracted considerable attention. Compared with the traditional superalloy material, the ceramic matrix composite material has the remarkable advantages of low density (the same volume is reduced by 2/3), high temperature resistance (the working temperature is increased by more than 200K), high hardness (> 2900 HV), high specific modulus, corrosion resistance, creep resistance, oxidation resistance and the like. Meanwhile, the ceramic matrix composite material is adopted for the turbine component of the aeroengine, so that the use of cooling gas can be reduced, the total pressure ratio (Overall Pressure Ratios, OPR), the turbine working efficiency and the combustion temperature are improved, the emission of harmful gases such as carbon monoxide (CO) and nitrogen oxides (NOx) is reduced, and the rotation rate of the blades is improved, so that the thrust is improved. Therefore, the ceramic matrix composite is hopefully the best choice for reducing weight and enhancing efficiency of turbine parts of aeroengines and replacing the traditional superalloy. However, the characteristics of the ceramic matrix composite, such as hardness and brittleness, also bring difficulty to the processing and manufacturing of the components, and the damages, such as edge breakage, tearing and the like, easily occur in the processing process, so that the processing efficiency and the processing quality are seriously affected. Especially, the special-shaped cooling air film hole of the ceramic matrix composite turbine blade has small size, complex structure and high requirements on precision and surface quality, and is a typical difficult processing problem. Because the ceramic matrix composite part is still in the basic pre-grinding stage in the field of development of the aeronautical engine, no mature method for processing the ceramic matrix composite special-shaped air film hole exists at home and abroad at present. The expert of northwest industrial university and China aviation engine institute puts forward a processing method of combining millisecond laser prefabricated holes with ultrasonic auxiliary mechanical drilling, and the ceramic matrix composite straight-round air film hole with better surface quality can be obtained, but the method is only suitable for processing straight round holes, is not suitable for processing and manufacturing the special-shaped air film hole with a special-shaped expansion section, and the mechanical processing method still has the problems of cutter abrasion and cost control. The expert of the northwest industrial university also provides a processing method for processing the micro-holes of the ceramic matrix composite material by femtosecond laser layering, so that the micro-holes with better surface quality are obtained, but the method is only applicable to processing straight round holes. Disclosure of Invention The invention aims to provide a processing method using ultra-fast laser, which is used for processing a special-shaped air film hole of a ceramic matrix composite material. According to the embodiment of the invention, the machining method comprises the steps of S1, S2, S3 and S4, wherein the step S1 is used for carrying out rotary cutting rough machining on an entity by using ultra-fast laser pulses to obtain a through first rough machining straight round hole, the step S2 is used for carrying out layered milling rough machining on the entity on the outer peripheral side of the partial depth of the first rough machining straight round hole by using ultra-fast laser pulses to obtain a rough machining abnormal hole and a second rough machining straight round hole which are communicated with each other, the step S3 is used for carrying out layered milling finish machining on the wall body of the rough machining abnormal hole by using ultra-fast laser pulses to obtain a finish machining abnormal hole, the finish machining abnormal hole is communicated with the second rough machining straight round hole, and t