The combined effect of extrusion and multi-directional forging (MDF) was investigated on microstructure and mechanical properties of aluminum-based composite with 10, 15, and 20 wt% Mg₂Si. In the casted Al–Mg₂Si composites, the primary and eutectic Mg₂Si particles are generally coarse which lead to decreasing their mechanical properties and formability. Extrusion process was utilized to overcome this shortcoming by breakage of the eutectic structure, reduction of Mg₂Si size, and the decrease of casting defects. Then, MDF process was applied up to failure on the extruded composites at room temperature. It led to the morphological modification of primary and eutectic Mg₂Si phases and the reduction of their size. It was found that the MDF process resulted in a considerable improvement in hardness and shear strength of materials. This may be related to the reduction in the average size of Mg₂Si particles with their uniform distribution. In addition, ultimate shear strength is, respectively, increased from 94, 99, and 81 MPa to 119, 116, and 117 MPa for the 10, 15, and 20 wt% Mg₂Si aluminum composites after the final pass of MDF. Meanwhile, the normal displacement of composites is reduced at initial passes and increased by the addition of more pass numbers.

中文翻译：

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研究热挤压和多向锻造对Al–Mg 2 Si复合材料的组织和力学性能的组合影响

研究了挤压和多方向锻造（MDF）对铝基复合材料（含10、15和20 wt％Mg ₂ Si ）的组织和力学性能的综合影响。在铸造的Al-Mg ₂ Si复合材料中，初生和共晶Mg ₂ Si颗粒通常较粗，这会导致其机械性能和成形性下降。通过挤压工艺克服了共晶结构的破坏，Mg ₂ Si尺寸的减小和铸造缺陷的减少的缺点。然后，在室温下将MDF工艺应用于挤出复合材料的破坏。它导致了初生和共晶Mg ₂的形态变化Si相及其尺寸的减小。发现MDF工艺导致材料的硬度和剪切强度的显着改善。这可能与Mg ₂ Si颗粒平均尺寸的减小及其均匀分布有关。另外，在MDF的最终通过之后，对于10、15和20wt％的Mg ₂ Si铝复合材料，极限剪切强度分别从94、99和81MPa增加到119、116和117MPa。同时，复合材料的法向位移在初次通过时减小，并且通过增加更多的通过次数而增加。