| Title |
The Effect of Second Phase particles on Fracture Properties of 2XXX Aluminum Composites Reinforced with SiC Whiskers |
| Authors |
이성학(S . Lee); 이태형(T . H . Kim); 김영환(Y . H . Kim); 조경목(K . Cho) |
| Abstract |
The purpose of this study is to explore the effects of the matrix alloy composition on fracture properties of the 2124 and the 2009 Al/SiCw composites and to attempt to assess the corresponding role of second phase particles such as coarse Mn-containing intermetallic particles. The contents of Mn and Fe were significantly reduced in the composition of the 2009 matrix alloy with respect to that of the 2124 alloy. Tensile tests, fracture tougness test and in-situ SEM fracture observations were conducted on these two composites. Experimental results indicated a higher toughness in the 2009 Al/SiC composite, although strengths were slightly decreased. The observations of fracture processes showed that coarse Mn-containing particles were cracked first and accentuated the formation of shear bands. Thus the improvement of fracture toughness in the 2009 Al/SiCw composite could be interpreted by the increase of the spacing between effective fracture initiation sites due to the absence of coarse Mn-containing particles. It is also suggested that another possible way of improving fracture toughness is to use SiC particulates as reinforcements instead of whiskers in order to modify the composite microstructure. |