| WU Dongjiang,CAI Xintong,LI Zheng,DONG Zhigang,MA Guangyi,BAO Yan,KANG Renke,NIU Fangyong.Cf/C-SiC Ablative Behavior and Feasibility of Laser Assisted Ultrasonic Grinding[J],53(4):162-174 |
| Cf/C-SiC Ablative Behavior and Feasibility of Laser Assisted Ultrasonic Grinding |
| Received:October 23, 2023 Revised:December 28, 2023 |
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| DOI：10.16490/j.cnki.issn.1001-3660.2024.04.015 |
| KeyWord:ceramic matrix composite laser ultrasonic assisted grinding multi-energy field micromorphology grinding force |
| Author | Institution |
| WU Dongjiang |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| CAI Xintong |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| LI Zheng |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| DONG Zhigang |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| MA Guangyi |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| BAO Yan |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| KANG Renke |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
| NIU Fangyong |
School of Mechanical Engineering, Dalian University of Technology, Liaoning Dalian , china |
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| Abstract: |
| The work aims to reveal the interaction mechanism between laser and Cf/C-SiC ceramic matrix composites, and analyze the effect of laser energy density on the shape evolution of the materials. A scheme of laser assisted ultrasonic grinding for Cf/C-SiC machining is proposed, and the feasibility of multi-energy field machining of hard and brittle materials is explored. In this work, a laser beam with different energy density was used to scan the surface of Cf/C-SiC ceramic matrix composite to investigate the effect of laser on the ablation pits, heat affected zone and crack zone. Then, parallel texture grooves with different spacing were preset on the surface of the material, and the machining effects of traditional grinding, ultrasonic assisted grinding and laser assisted ultrasonic grinding were compared. Meanwhile, the effect of laser prefabricated grooves with different scanning spacing on ultrasonic grinding was studied. The surface temperature of the sample was measured by infrared thermal imager. The macro and micro morphology and element composition of the sample section were analyzed by ultra-depth of field microscope, scanning electron microscope and energy spectrometer. The grinding force and machining quality were measured by dynamometer and 3D surface optical profilometer. Under the action of laser, CMC showed two different states. In the modified state, the material was dominated by oxidation and other thermochemical changes. The materials underwent oxidation of SiC phase, C fiber and pyrolytic carbon, liquefaction of Si phase, formation of gaseous SiO, and evaporation of SiO2 after liquefaction, and the cross section had heat affected zone and crack zone, in which the continuous phase in the heat affected zone disappeared. In the ablative state, in addition to the reaction in the modified state, sublimation of SiC phase, C fiber and pyrolytic carbon interface, SiC decomposition and Si phase gasification also occurred. At this time, the material was mainly corroded by thermophysical and thermomechanical reaction, and there were ablative pits, recast layers, heat affected zones and crack zones in the sample section. The formation of pits and cracks was conducive to subsequent machining. When the interface of the fiber bundle underwent the whole debonding, the cracks extended downward and deflected. The cracks in the matrix mostly originated at the fiber interface, and were deflected, bifurcated and bridged during the process of expansion, and there were both transgranular and intergranular fractures at the same time. When the laser scanning spacing was 2, 1 and 0.5 mm, the average depth of the laser prefabricated groove was 547, 568 and 677 μm, respectively. The average grinding force in X direction and Y direction was 0.248 N and 0.403 N, and the surface roughness was about 4.228 μm. Compared with traditional grinding, the average grinding force in both directions was reduced by 51.4% and 56.5%, and the surface roughness could be reduced. The results show that laser assisted ultrasonic grinding can effectively reduce the grinding force, and can reduce the roughness of the machined surface to a certain extent, so as to improve the machining quality. For hard and brittle materials, laser combined ultrasonic grinding has great potential in increasing grinding parameters, improving efficiency and realizing high quality and low-cost machining. |
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