Effects of in-situ TiB2 particles on machinability and surface integrity in milling of TiB2/2024 and TiB2/7075 Al composites
| Autor: | Jiwei Geng, Dong Chen, Jie Chen, Qinglong An, Haowei Wang, Zhenyu Zuo, Weiwei Yu, Ming Chen, Yu-gang Li |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0209 industrial biotechnology
Machinability Materials science Composite number Aerospace Engineering TiB2 particle 02 engineering and technology 01 natural sciences 010305 fluids & plasmas 020901 industrial engineering & automation Machining 0103 physical sciences Ultimate tensile strength Surface roughness Ceramic Composite material Milling Motor vehicles. Aeronautics. Astronautics Aluminum matrix composites Mechanical Engineering TL1-4050 Surface integrity visual_art visual_art.visual_art_medium Particle |
| Zdroj: | Chinese Journal of Aeronautics, Vol 34, Iss 6, Pp 110-124 (2021) |
| ISSN: | 1000-9361 |
| Popis: | In-situ ceramics particle reinforced aluminum matrix composites are favored in the aerospace industry due to excellent properties. However, the hard ceramic particles as the reinforcement phase bring challenges to machining. To study the effect of in-situ TiB2 particles on machinability and surface integrity of TiB2/2024 composite and TiB2/7075 composite, milling experiments were performed, and compared with conventional 2024 and 7075 aluminum alloys. In-situ TiB2 particles clustered at the grain boundaries and dispersed inside the matrix alloy grains hinder the dislocation movement of the matrix alloy. Therefore, the milling force and temperature of the composites are higher than those of the aluminum alloys due to the increase of the strength and the decrease of the plasticity. In the milling of composites, abrasive wear is the main wear form of carbide tools, due to the scratching of hard nano-TiB2 particles. The composites containing in-situ TiB2 particles have machining defects such as smearing, micro-scratches, micro-pits and tail on the machined surface. However, in-situ TiB2 particles impede the plastic deformation of the composites, which greatly reduces cutting edge marks on the machined surface. Therefore, under the same milling parameters, the surface roughness of TiB2/2024 composite and TiB2/7075 composite is much less than that of 2024 and 7075 aluminum alloy respectively. Under the milling conditions of this experiment, the machined subsurface has no metamorphic layer, and the microhardness of the machined surface is almost the same as that of the material. Besides, compared with 2024 and 7075 aluminum alloy, machined surfaces of TiB2/2024 composite and TiB2/7075 composite both show tensile residual stress or low magnitude of compressive residual stress. |
| Databáze: | OpenAIRE |
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