Microtomography and Creep Modeling of a Short Fiber Reinforced Aluminum Piston Alloy

Abstract

Short fiber reinforced metals (SFRMs) have shown promising mechanical properties at elevated temperature, [1] leading to applications for combustion engines where some components locally reinforced with short fibers (SFs) have been developed. [2][3][4] To ensure the reliability of such materials under long-term temperature/load exposure, the mechanisms controlling their thermomechanical behavior are to be known.In previous studies, [3,5] an SF reinforced AlSi12CuMgNi alloy showed a decrease in stationary creep rate with the creep exposure time extending several thousand hours at 300 8C. Microtomographic evaluations [5] revealed microstructural changes of the Si phase, specially of the interconnectivity between Si, SFs, and intermetallics.Models of creep behavior of SFRM have focused on the spatial arrangement of the fibers, [6] the influence of damage, [7] the work hardened zone between matrix and fibers, [8][9][10] and the constitutive creep law of the matrix material [11] but few have studied the influence of the interpenetrating architecture of the rigid phases (e.g., ref.[12]).In the present investigation a three-dimensional (3D) unit cell finite element (FE) model is proposed in order to study the influence of the 3D connectivity between Si and SFs on the creep resistance of AlSi-based SFRM. This simple model is based on 3D microstructural features and it is correlated with experimental results. Experimental

The Effect of the Connectivity of Rigid Phases on Strength of AlSi Alloys

“…The effect of the connectivity between Si and the ceramic short fibres on creep resistance was investigated in ref 34. by finite element simulations using visco‐plastic unit cell models.…”

“…by finite element simulations using visco‐plastic unit cell models. For this, two unit cell geometric models representing extreme conditions of Si‐SFs connectivity were developed:34 one consisting of isolated Si particles and short fibres embedded in the Al‐matrix [Fig. 6(a)] and the second with a structure of short fibres fully interconnected by Si embedded in the Al‐matrix [Fig.…”

“…The shadowed region highlights the larger fraction of regions at higher stresses obtained the model with 0% interconnectivity. The arrows in (a) and (b) indicate the direction of the external load 34…”

Fabrication of glass/carbon fiber-reinforced Al-based composites through deformation bonding

“…The short fiber-reinforced composites exhibit promising behavior at high temperature applications such as combustion engines and pistons. 8,9…”