Aluminum Matrix Composites with Weak Particle Matrix Interfaces: Effective Elastic Properties Investigated Using Micromechanical Modeling

Abstract

The impact of weak particle-matrix interfaces in aluminum matrix composites (AMCs) on effective elastic properties was studied using micromechanical finite-element analysis. Both simplified unit cell representations (i.e., representative area or volume elements) and “real” microstructure-based unit cells were considered. It is demonstrated that a 2D unit cell representation provides accurate effective properties only for strong particle-matrix bond conditions, and underpredicts the effective properties (compared to 3D unit cell computations) for weak interfaces. The computations based on real microstructure of an Al–TiB2 composite fabricated using spark plasma sintering (SPS) show that, for weak interfaces, the effective elastic properties under tension are different from those obtained under compression. Computations show that differences are the result of the local stress and strain fields, and contact mechanics between particles and the matrix. Preliminary measurements of the effective elastic properties using the ultrasonic pulse-echo technique and compression experiments support the trends observed in computational analysis.

Small punch testing of Al-TiB2 composites fabricated by spark plasma sintering: A computational and experimental study

“…The elastic constants for the different Al-TiB 2 compositions determined in 18 and used in the computational analysis are given in Table 1.…”

“…It is assumed that a continuum approach for modelling the composite represents well the constitutive response, as the cross-section of the material contains a large number of grains, as can be seen for all representative volume fractions in Figure 2. The authors previously identified the effective elastic parameters in 18 and the effective flow stresses are based on the values reported by the authors in. 13 However, the current batch of specimens was manufactured with some differences in the SPS parameters with respect to.…”

“…The elastic constants for the different Al-TiB 2 compositions determined in 18 and used in the computational analysis are given in Table 1. The final flow stress parameters following the iterative process for the different composition using the Holloman representation σ t ¼ Kε n are given in Table 2.…”

New Numerical Method Based on Linear Damage Evolution Law for Predicting Mechanical Properties of TiB2/6061Al

“…Aside from experimental and theoretical analytical methods, the microstructure-based representative volume element (RVE) has also been increasingly adopted to study double-phase composites [ 15 , 16 , 17 ]. Wang et al [ 16 ] proposed a 2D RVE of SiC/Al and studied its mechanical behavior by introducing the discrete distribution function of reinforcement.…”

Лагранжев Формализм Для Анализа Акустических Свойств Двухфазных Композитных Материалов С Дефектными Межфазными Границами

“…Для такой среды строится система определяющих соотношений с учетом условий для напряжений и деформаций на внутренних границах раздела (интерфейсах). В общем случае такая система уравнений решается численно, а усреднение получаемых результатов для представительных мезообъемов позволяет оценивать эффективные свойства композита [7][8][9][10][11][12][13]. Несмотря на хорошо известные преимущества (возможность явного учета микроструктуры и особых свойств интерфейсов), непосредственная компьютерная гомогенизация является вычислительно крайне затратной процедурой вследствие необходимости проведения многопараметрического исследования для определения однозначного соответствия внутренней структуры и макроскопических свойств материала.…”