Microstructural and mechanical behavior of blended powder semisolid formed A17075/B4C composites under different experimental conditions

作者：Javdani A; Daei Sorkhabi A H^*

来源：Transactions of Nonferrous Metals Society of China, 2018, 28(7): 1298-1310.

DOI：10.1016/S1003-6326(18)64767-3

• blended powder
• mechanical alloying
• semisolid forming
• B4C
• aluminum matrix composite

This work aimed to fabricate B4C reinforced aluminum matrix composites via blended powder semisolid forming that is an implementation of the benefits of semisolid forming to the powder metallurgy. A17075 elements were incrementally added to ethanol solution under mechanical mixing. A17075 constituents and B4C particles were blended in a high energy ball mill. Cold compacted A17075/B4C blends were pressed at semisolid state. The effects of the size of the matrix (20, 45 and 63 mu m), reinforcing volume fraction (5%, 10% and 20%) and semisolid compaction pressure (50 and 100 MPa) on the morphology, microstructure, density, hardness, compression and bending strength were thoroughly analyzed. Experimental results revealed that the highest micro structural uniformity was achieved when large B4C particles (45 mu m) were distributed within the small particles (20 mu m) of the matrix phase. Composites with matrix particles larger than reinforcing phase indicated agglomerations in loadings more than 10% (volume fraction). Agglomerated regions resisted against penetration of the liquid phase to the pores and lowered the density and strength of these composites. Composites with 20 mu m A17075 and 20% (volume fraction) 45 mu m B4C powder pressed under 100 MPa exhibited the highest values of hardness (HV 190) and compressive strength (336 MPa).

• 出版日期2018-7