EFFECT OF EXTRUSION PARAMETERS ON STRUCTURE AND PROPERTIES OF 2124 ALUMINUM ALLOY MATRIX COMPOSITES
EFFECT OF EXTRUSION PARAMETERS ON STRUCTURE AND PROPERTIES OF 2124 ALUMINUM ALLOY MATRIX COMPOSITES
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DOI：
10.1081/amp-100108703
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发表时间：
2001-06
影响因子：
4.8
通讯作者：
V. V. B. Prasad-V.;B. Bhat;Y. Mahajan;P. Ramakrishnan;Kanchan Bagh;B. Prasad
中科院分区：
文献类型：
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作者：
V. V. B. Prasad-V.;B. Bhat;Y. Mahajan;P. Ramakrishnan;Kanchan Bagh;B. Prasad
非连续增强铝基复合材料因其易受传统金属加工工艺的变形加工而备受关注。挤压是用于处理DRA复合材料的固结，增强再分配和形状形成。控制挤压过程的重要参数是温度和应变速率，这是几个设备/挤压参数的函数。采用真空热压（VHP）挤压2124 Al/ 30sicp复合坯料，采用不同的挤压速度（1、10、100 mm秒−1）和不同的挤压比（4:1、10:1和20:1）。研究了挤压试样的完整性、微观结构和力学性能。在最小挤压速度为1 mm秒−1时，挤压棒的完整性非常好，而100 mm秒−1的挤压速度导致大量杉木开裂。VHP坯料挤压呈项链状结构，挤压方向上基体与SiCp呈细长交错串状。坯料长径比和宽径比随挤压比的变化而变化。由于微观组织的细化，金属基复合材料的强度和延展性都得到了提高。发现，与位置和挤压比无关，基体弦条的显微硬度是宽度的函数（幂函数关系）。
Discontinuously reinforced aluminum matrix composites (DRA) have been attracting attention because of their amenability to undergo deformation processing by conventional metalworking techniques. Extrusion is used in processing of DRA composites for consolidation, redistribution of reinforcements, and shape forming. The important parameters that control the extrusion process are temperature and strain rate, which is a function of several equipment/extrusion parameters. Vacuum hot-pressed (VHP) 2124 Al/30 SiCp composite billets were extruded at different ram speeds (1, 10, 100 mm sec−1) and using different extrusion ratios (4:1, 10:1, and 20:1). The extruded samples were studied for their integrity, microstructure, and mechanical properties. The integrity of the extruded composite rod was very good at minimum extrusion speed of 1 mm sec−1, whereas 100 mm sec−1 extrusion speed resulted in extensive fir tree cracking. Extrusion of VHP billets, with necklace structure, resulted in elongated alternate stringers of matrix and SiCp in the extrusion direction. Matrix stringer width and aspect ratio were found to vary with extrusion ratio. Because of the microstructural refinement, both the strength and ductility of the metal matrix composites (MMCs) were improved. Microhardness of the matrix stringers was found to be a function (power relation) of their width, irrespective of the location and extrusion ratio.