Silicon carbide and 2024 aluminum alloy powders with average particle sizes of 14 μm and 15 μm are selected as the reinforcement phase and matrix alloy, respectively. SiCp/2024Al composites with volume fractions of 35%, 45%, and 55% are fabricated by hot isostatic pressing. The influence of aging treatment on the mechanical properties of the composites is investigated. The results show that aging treatment significantly enhances the hardness of the composites. Increasing the aging temperature and the volume fraction of SiC both shorten the peak aging time of the composites. When the aging temperature is increased from 160 ℃ to 190 ℃, the peak aging time of the composite with a 35% volume fraction is reduced from 9.5 h to 2 h. At 190 ℃, the peak aging time of all three volume fraction composites is shortened to 2 h. The precipitation strengthening of the matrix alloy during the heat treatment process results in higher flexural strength in the aged composites compared to the as-sintered composites with the same volume fraction. The higher the matrix alloy content, the more significant the strengthening effect. Among them, the peak-aged composite with a 35% volume fraction exhibits the highest flexural strength, reaching 901 MPa at 170 ℃. With the increase of volume fraction, the matrix alloy content decreases, reducing the ability of the material to alleviate local stress concentration through plastic deformation. Moreover, defects in the composites gradually increase. Therefore, both the as-sintered and heat-treated composites with a 55% volume fraction exhibit lower flexural strength. However, the micro-yield strength of the aged composites is higher than that of the as-sintered composites. The aged composite with a 45% volume fraction generally has the highest micro-yield strength, fluctuating in the range of 361-380 MPa, while the aged composite with a 55% volume fraction has the lowest micro-yield strength. The micro-yield strength of the composite with a 35% volume fraction initially increases and then decreases with increasing temperature, reaching its highest value (368 MPa) at 180 ℃, slightly higher than that of the composite with a 45% volume fraction under the same conditions.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |