Further investigation of particle reinforced aluminum matrix composites by indentation experiments
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a Zahid Hussain School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072, China (Received 24 June 2013; accepted 13 January 2014)
In this paper, a modeling method was introduced for SiC particle reinforced aluminum matrix composite. Micro-indentation technique was used to study the micro properties of both SiC particles and aluminum matrix with Micro-Compression-Tester. Mechanical properties like Young’s modulus and hardness were calculated using Oliver and Pharr method. After repeated experiments, the average Young’s modulus and the hardness of matrix and particle were calculated as 76.8 and 334.7 GPa, 1.58 and 32.56 GPa, respectively. During the indentation experiments on particle, the phenomenon of particle acting as “second indenter” was detected from the recorded P–h curves. Besides, the material elastic–plastic properties of matrix were analyzed using inverse method. Based on the micro material properties from indentation, the indentation processing of particle as second indenter has been simulated. Also, the simulation model at micro scale has been established by using such material properties for further investigation.
I. INTRODUCTION
Due to the nondestructive nature of hardness testing, it has been widely used to study mechanical properties like Young’s modulus and hardness since long.1–5 So far, a wide range of literature is available on the microstructure and macroscopic mechanical behavior of materials based upon indentation testing (hardness test). Among various issues, forward problem and inverse problem are two hot topics for years. As forward problem, a model proposed by Tabor6 in the 1950s had well explained the relation between hardness and flow stress, i.e., H 5 krr, where H is hardness at flow stress corresponding to strain of 8% and constraint coefficient k as a constant equal to 3. Later, Cheng and Cheng has done plenty of works7–9 and gave a relationship between hardness and the basic mechanical properties of solids like Young’s modulus, initial yield strength, and work-hardening exponent with certain indenter shape. According to Wei and Hutchinson,10 indentation measured hardness is a function of the variables like size of the indenter relative to the material length parameters, the strain hardening exponent, the ratio of initial yield stress to Young’s modulus, and the geometry of the indenter. Haj-Ali et al.11 has analyzed the indentation response to nanohardness tests for a variety of materials with nonlinear behavior by adopting artificial neural networks. Recently, Cao et al.12 had studied the a)
Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2014.15 586
J. Mater. Res., Vol. 29, No. 4, Feb 28, 2014
http://journals.cambridge.org
Downloaded: 17 Mar 2015
sharp indentation in soft metals and found a simple relation between the nominal hardness and the flow stress. With regard to inverse problems, indentation results are used to extract the elastic–plastic properties of materials. Among the various methods, Dao et
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