Evaluation of strengthening behavior of Al–AlN nanostructured composite by the use of modified Heckel model and response surface methodology

Farnoush, Hamidreza; Haghshenas, Davoud Fatmehsari; Mohandesi, Jamshid Aghazadeh; Abdoli, Hamid

doi:10.1016/j.jallcom.2011.11.138

Cited by 9 publications

(5 citation statements)

References 40 publications

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“…The result agrees with the previously reported theory, which claimed that the changes in shear stress as a function of compact porosity could affect polymorphic interconversion of CPA . The reversed form C-to-A conversion during dwelling and decompression in this region is particularly lower than expected because particles may have undergone fragmentation and plastic deformation in region II. − Interestingly, the stress changes (Δ P ) do not increase anymore (Figure A) and reverse conversion from C to A during dwelling is negligible (Figure A). Based on the Heckel plot, we observed that the relative density changes (Δ ln[1/(1 – D)]) are minor, suggesting the minor extent of elastic recoveries in decompression (Figure B).…”

Section: Results and Discussionsupporting

confidence: 91%

“…The yield pressure ( P y ) was calculated (Table ) based on the Heckel plot for both the compression and unloading/decompression processes. Theoretically, the plastic deformation and fragmentation of particles occur at P y , indicating that the powder compacts are formed and densified predominantly by forming interparticulate bonding. − …”

Section: Results and Discussionmentioning

confidence: 99%

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Understanding Dynamics of Polymorphic Conversion during the Tableting Process Using In Situ Mechanical Raman Spectroscopy

et al. 2020

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The objective of this study is to achieve a fundamental understanding of polymorphic interconversion during the tableting process, including during compaction, dwell, decompression/unloading, and ejection using an in situ mechanical Raman spectroscopy. The fit-for-purpose in situ mechanical Raman spectroscopy developed herein can provide simultaneous measurement of Raman spectra and densification for the powder compacts. Chlorpropamide (CPA), an antidiabetic drug, was selected as a model pharmaceutical compound because of its mechanical shear-induced polymorphic conversions. The results confirm that CPA polymorph A (CPA-A) was transformed to CPA polymorph C (CPA-C) under different compaction stresses. We also observed that the converted polymorph CPA-C could be reverted to the CPA-A due to the elastic recovery of powder compacts as detected during dwelling and unloading. This study is the first depiction of the dynamics of CPA polymorphic interconversion during compression, dwell, unloading, and ejection. Mechanistically, this study illustrates a correlation between the change in the powder compact’s relative density and polymorphic interconversion of the drug substance in different solid-state forms. The present research suggests that the process-induced polymorph conversion is a complicated dynamic process, which could be affected by the compaction pressure, the elasticity/plasticity of the material, the level of elastic recovery, and the dissipation of residual stress. In summary, this study demonstrates that the in situ mechanical Raman spectroscopy approach enables the simultaneous detection of mechanical and chemical information of the powder compact throughout the tableting process.

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Section: Results and Discussionsupporting

confidence: 91%

Section: Results and Discussionmentioning

confidence: 99%

Understanding Dynamics of Polymorphic Conversion during the Tableting Process Using In Situ Mechanical Raman Spectroscopy

et al. 2020

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“…Irregular morphology causes the formation of asymmetrical forces opposing contact points, resulting in shear strain and consequently cold welding of powders [14,15]. Different authors report that densification decreases as milling time increases [16,17]. In the present work, this behavior is followed by the Cu-5Al matrix for milling times of 0 and 2 h during the full pressure range, and for all the samples up to 109.9 MPa of pressure (Fig.…”

Section: Compressibility Of Powderssupporting

confidence: 49%

Densification Study of Cu-Al-SiC Composite Powders Prepared by Mechanical Milling

León‐Patiño

Ramírez-Vinasco

Aguilar-Reyes

2014

MSF

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This work involves the preparation of Cu-Al-SiC composite powders by a high-energy milling process and the study of their densification behavior by cold compaction. The goal of the milling process is to get embedded the ceramic particles in the metal matrix to enhance the distribution of the metal and ceramic phases in the compacts, an important condition to derive in isotropic properties of consolidated materials. For comparison purposes, compressibility tests of a Cu-5Al matrix prepared by high-energy milling were performed; while additions of 1, 5 and 10 vol.% SiC were added to the matrix. It was found that the high-energy milling process leads to Cu-Al-SiC composite powders with a homogeneous distribution of the reinforcement in the matrix. Compressibility essays showed that densification of the powders decreased with SiC content; a densification of 73.7% was obtained for composites with 10% SiC compared to 76.0% for samples with 1% SiC at the maximum load applied. Milling time reduced the plastic deformation capacity of the matrix leading to fracture of the cold welded aggregates; the fracture process was accelerated by the addition of the hard reinforcement particles. Thus, morphology of the powders changed from laminar, to fine fragments and coarse aggregates, affecting the compaction behavior.

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“…In order to clarify the simultaneous effect of the pertinent parameters and their probable interactions on the compressive properties of TMFs, response surface methodology (RSM) based on a central composite design (CCD) is used [18][19][20]. For quantification of the effects of cell diameter, cell wall thickness, height of the cell layers on the structural stiffness, yield and compressive strength, RSM-CCD is coupled with the finite element simulation.…”

Section: Introductionmentioning

confidence: 99%

Compressive behavior of tailor-made metallic foams (TMFs): Numerical simulation and statistical modeling

2015

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Evaluation of strengthening behavior of Al–AlN nanostructured composite by the use of modified Heckel model and response surface methodology

Cited by 9 publications

References 40 publications

Understanding Dynamics of Polymorphic Conversion during the Tableting Process Using In Situ Mechanical Raman Spectroscopy

Understanding Dynamics of Polymorphic Conversion during the Tableting Process Using In Situ Mechanical Raman Spectroscopy

Densification Study of Cu-Al-SiC Composite Powders Prepared by Mechanical Milling

Compressive behavior of tailor-made metallic foams (TMFs): Numerical simulation and statistical modeling

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