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1 pages, 145 KiB

Open AccessEditorial

Special Issue “Lightweight Structural Materials for Automotive and Aerospace”

by Frank Czerwinski

Materials 2022, 15(20), 7089; https://doi.org/10.3390/ma15207089 - 12 Oct 2022

Cited by 2 | Viewed by 1324

Abstract

Modern transport represents a vital part of the global economy, but it is also a significant source of pollutants, contributing 13% of overall greenhouse gas and 25% of CO₂ emissions coming from the combustion of fossil fuels [...] Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

Research

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22 pages, 17317 KiB

Open AccessArticle

Numerical Investigation into In-Plane Crushing of Tube-Reinforced Damaged 5052 Aerospace Grade Aluminum Alloy Honeycomb Panels

by Younes Djemaoune, Branimir Krstic, Stefan Rasic, Daniel Radulovic and Marjan Dodic

Materials 2021, 14(17), 4992; https://doi.org/10.3390/ma14174992 - 1 Sep 2021

Cited by 12 | Viewed by 3170

Abstract

This paper aims to investigate the crashworthiness performance degradation of a damaged 5052 aluminum honeycomb panels under in-plane uniaxial quasi-static compression and the possibility of improving it using reinforcement tubes. The in-plane crushing behaviors and energy absorption capacities of the intact, damaged, and [...] Read more.

This paper aims to investigate the crashworthiness performance degradation of a damaged 5052 aluminum honeycomb panels under in-plane uniaxial quasi-static compression and the possibility of improving it using reinforcement tubes. The in-plane crushing behaviors and energy absorption capacities of the intact, damaged, and tube-reinforced damaged panels with different damage sizes in both X₁ and X₂ directions are numerically simulated by using the nonlinear FE method Abaqus/Explicit, and the crashworthiness performances are compared with each other. The validation of finite element model involves comparing the obtained simulation results with theoretical and experimental ones. Very good agreement between numerical, experimental, and theoretical results is achieved. The first maximum compressive load and the mean crushing load of the different honeycomb configurations are analyzed and compared through the load–strain curves. The energy absorption capacity of the damaged and the tube-reinforced damaged panels is calculated and then compared with their corresponding intact ones. The deformation modes are explained in detail. The obtained results show that the crashworthiness performance degradation is directly proportional to the damage size as well as the insertion of reinforcement tubes considerably improves in-plane crushing resistance of damaged honeycomb panels. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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18 pages, 10547 KiB

Open AccessArticle

Impact of Carbon Foam Cell Sizes on the Microstructure and Properties of Pressure Infiltrated Magnesium Matrix Composites

by Anita Olszówka-Myalska, Marcin Godzierz and Jerzy Myalski

Materials 2020, 13(24), 5619; https://doi.org/10.3390/ma13245619 - 9 Dec 2020

Cited by 5 | Viewed by 2082

Abstract

Magnesium-based composites reinforced with open-celled carbon foams (C_of) of porosity approx. 97 vol % and three cell sizes (20, 45 and 100 ppi) were examined to characterize the influence of foam cell size on the microstructure and properties when pure magnesium [...] Read more.

Magnesium-based composites reinforced with open-celled carbon foams (C_of) of porosity approx. 97 vol % and three cell sizes (20, 45 and 100 ppi) were examined to characterize the influence of foam cell size on the microstructure and properties when pure magnesium and two cast alloys AZ31 and RZ5 were used as matrices. All composites were fabricated by pressure infiltration under the same conditions (temperature, pressure, time). For each matrix composition, two main factors due to the presence of the foam determined the composite microstructure—the efficiency of foam penetration and different conditions of metal crystallization. The lowest porosity was obtained when C_of45ppi was used and was independent of the applied matrix composition. The metallic component microhardness increased with a decrease in the carbon cell size as well as a decrease in the α-Mg grain size; both of those results should be taken into account during theoretical calculations. Compression and three-point bending strength measurements showed increases as the carbon cell size decreased, but reinforcing effectiveness relative to the matrix material depended on the metal matrix composition. At the fractured surface, different structural effects in the foam and matrix as well as at the interface were observed and depended on the foam geometry, metal composition and mechanical test type. In glassy carbon foam, those effects occurred as cracking across walls, fragmentation, and delamination, while in the matrix, shear bands and intergranular cracking were observed. On the delaminated foam surface, the microareas of a thin oxide layer were detected as well as dispersed phases characteristic for the applied matrix alloys. The accumulation of intermetallic phases was also observed on the metal matrix surface in microareas delaminated from the carbon foams. Mechanical property results indicated that among the tested, open-celled, carbon foams a 45 ppi porosity was the most useful for pressure infiltration and independent of magnesium-based matrix composition. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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27 pages, 10395 KiB

Open AccessFeature PaperArticle

On the Al–Al₁₁Ce₃ Eutectic Transformation in Aluminum–Cerium Binary Alloys

by Frank Czerwinski and Babak Shalchi Amirkhiz

Materials 2020, 13(20), 4549; https://doi.org/10.3390/ma13204549 - 13 Oct 2020

Cited by 58 | Viewed by 5156

Abstract

The L ↔ Al + Al₁₁Ce₃ technologically important eutectic transformation in Al–Ce binary alloys, containing from 5 to 20 wt.% Ce and ranging from hypo- to hypereutectic compositions, was examined along with the microstructure and properties of its solidified product. [...] Read more.

The L ↔ Al + Al₁₁Ce₃ technologically important eutectic transformation in Al–Ce binary alloys, containing from 5 to 20 wt.% Ce and ranging from hypo- to hypereutectic compositions, was examined along with the microstructure and properties of its solidified product. A combination of thermal analysis and metallography determined the coordinates of the eutectic point at 644.5 ± 0.6 °C and 10.6 wt.% Ce, clarifying the existing literature ambiguity. Despite the high entropy of melting of the Al₁₁Ce₃ phase, in hypoeutectic alloys the eutectic was dominated by the regular morphology of periodically arranged lamellae, typical for non-faceted systems. In the lamellar eutectic, however, the faceting of Al₁₁Ce₃ was identified at the atomic scale. In contrast, for hypereutectic compositions, the Al₁₁Ce₃ eutectic phase exhibited complex morphology, influenced by the proeutectic Al₁₁Ce₃ phase. The Al₁₁Ce₃ eutectic phase lost its coherency with Al; it was deduced that a partial coherency was present only at early stages of lamellae growth. The orientation relationships between the Al₁₁Ce₃ and Al in the eutectic structure, leading to partial coherency, were determined to be

[0 0 1]

_Al ║

[\bar{1} 1 1]

_Al11Ce3 with

(0 4 \bar{4})

_Al ║

(\bar{2} 0 0)

_Al11Ce3 and

[0 1 1]

_Al ║

[\bar{3} 0 1]

_Al11Ce3 with

(\bar{2} 0 0)

_Al ║

(0 6 0)

_Al11Ce3. The Al₁₁Ce₃ phase with a hardness of 350 HV and Al matrix having 35 HV in their eutectic arrangement formed in situ composite, with the former playing a role of reinforcement. However, the coarse and mostly incoherent Al₁₁Ce₃ eutectic phase provided limited strengthening and the Al–Ce alloy consisting of 100% eutectic reached at room temperature a yield stress of just about 70 MPa. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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17 pages, 7153 KiB

Open AccessArticle

Effect of Compound Fields of Ultrasonic Vibration and Applied Pressure on the 3D Microstructure and Tensile Properties of Recycled Al-Cu-Mn-Fe-Si Alloys

by Yuliang Zhao, Bo Lin, Dongfu Song, Donghai Zheng, Zhenzhong Sun, Chunxiao Xie and Weiwen Zhang

Materials 2019, 12(23), 3904; https://doi.org/10.3390/ma12233904 - 26 Nov 2019

Cited by 22 | Viewed by 2731

Abstract

The effect of compound fields of ultrasonic vibration and applied pressure (UV+AP) on three-dimensional (3D) microstructure and tensile properties of recycled Al-Cu-Mn-Fe-Si alloys was systematically studied using conventional two-dimensional (2D) microscopy, synchrotron X-ray tomography, and tensile test. The properties of UV+AP treated alloys [...] Read more.

The effect of compound fields of ultrasonic vibration and applied pressure (UV+AP) on three-dimensional (3D) microstructure and tensile properties of recycled Al-Cu-Mn-Fe-Si alloys was systematically studied using conventional two-dimensional (2D) microscopy, synchrotron X-ray tomography, and tensile test. The properties of UV+AP treated alloys with the pouring temperature of 740, 710 and 680 °C were compared when those alloys achieved after gravity casting. After UV+AP treatment, the alloy with pouring temperature of 710 °C show the smallest grain size. Also, the sizes of Fe-rich phases and Al₂Cu are greatly reduced and their 3D morphologies are compacted. The mechanical properties of UV+AP treated alloys are relatively higher than those measured for gravity cast equivalents. This improvement can be explained by the synergistic effect of acoustic cavitation, acoustic streaming, and force-feeding, which resulted in the dendrite fragmentation, uniform solute distribution, and microstructural refinement. The Orowan strengthening and solution strengthening were identified as the main strengthening mechanisms. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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Review

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27 pages, 6708 KiB

Open AccessReview

Critical Minerals for Zero-Emission Transportation

by Frank Czerwinski

Materials 2022, 15(16), 5539; https://doi.org/10.3390/ma15165539 - 12 Aug 2022

Cited by 4 | Viewed by 5921

Abstract

Fundamentals of critical minerals and their paramount role in the successful deployment of clean energy technologies in future transportation are assessed along with current global efforts to satisfy the needs of automotive supply chains and environmental concerns. An implementation of large quantities of [...] Read more.

Fundamentals of critical minerals and their paramount role in the successful deployment of clean energy technologies in future transportation are assessed along with current global efforts to satisfy the needs of automotive supply chains and environmental concerns. An implementation of large quantities of minerals, in particular metals, into the manufacturing of strategic components of zero-emission vehicles will bring new challenges to energy security. As a result, a reduced dependency on conventional hydrocarbon resources may lead to new and unexpected interdependencies, including dependencies on raw materials. It is concluded that to minimize the impact of a metal-intensive transition to clean transportation, in addition to overcoming challenges with minerals mining and processing, further progress in understanding the properties of critical materials will be required to better correlate them with intended applications, to identify potential substitutions and to optimize their use through the sustainable exploration of their resources and a circular economy. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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27 pages, 8866 KiB

Open AccessReview

Current Trends in Automotive Lightweighting Strategies and Materials

by Frank Czerwinski

Materials 2021, 14(21), 6631; https://doi.org/10.3390/ma14216631 - 3 Nov 2021

Cited by 210 | Viewed by 29059

Abstract

The automotive lightweighting trends, being driven by sustainability, cost, and performance, that create the enormous demand for lightweight materials and design concepts, are assessed as a part of the circular economy solutions in modern mobility and transportation. The current strategies that aim beyond [...] Read more.

The automotive lightweighting trends, being driven by sustainability, cost, and performance, that create the enormous demand for lightweight materials and design concepts, are assessed as a part of the circular economy solutions in modern mobility and transportation. The current strategies that aim beyond the basic weight reduction and cover also the structural efficiency as well as the economic and environmental impact are explained with an essence of guidelines for materials selection with an eco-friendly approach, substitution rules, and a paradigm of the multi-material design. Particular attention is paid to the metallic alloys sector and progress in global R&D activities that cover the “lightweight steel”, conventional aluminum, and magnesium alloys, together with well-established technologies of components manufacturing and future-oriented solutions, and with both adjusting to a transition from internal combustion engines to electric vehicles. Moreover, opportunities and challenges that the lightweighting creates are discussed with strategies of achieving its goals through structural engineering, including the metal-matrix composites, laminates, sandwich structures, and bionic-inspired archetypes. The profound role of the aerospace and car-racing industries is emphasized as the key drivers of lightweighting in mainstream automotive vehicles. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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49 pages, 14823 KiB

Open AccessReview

Thermal Stability of Aluminum Alloys

by Frank Czerwinski

Materials 2020, 13(15), 3441; https://doi.org/10.3390/ma13153441 - 4 Aug 2020

Cited by 125 | Viewed by 16937

Abstract

Thermal stability, determining the material ability of retaining its properties at required temperatures over extended service time, is becoming the next frontier for aluminum alloys. Its improvement would substantially expand their range of structural applications, especially in automotive and aerospace industries. This report [...] Read more.

Thermal stability, determining the material ability of retaining its properties at required temperatures over extended service time, is becoming the next frontier for aluminum alloys. Its improvement would substantially expand their range of structural applications, especially in automotive and aerospace industries. This report explains the fundamentals of thermal stability; definitions, the properties involved; and the deterioration indicators during thermal/thermomechanical exposures, including an impact of accidental fire, and testing techniques. For individual classes of alloys, efforts aimed at identifying factors stabilizing their microstructure at service temperatures are described. Particular attention is paid to attempts of increasing the current upper service limit of high-temperature grades. In addition to alloying aluminum with a variety of elements to create the thermally stable microstructure, in particular, transition and rare-earth metals, parallel efforts are explored through applying novel routes of alloy processing, such as rapid solidification, powder metallurgy and additive manufacturing, engineering alloys in a liquid state prior to casting, and post-casting treatments. The goal is to overcome the present barriers and to develop novel aluminum alloys with superior properties that are stable across the temperature and time space, required by modern designs. Full article

(This article belongs to the Special Issue Lightweight Structural Materials for Automotive and Aerospace)

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