The Role of Technological Process in Structural Performances of Quasi-Crystalline Al–Fe–Cr Alloy

The present study emphasizes the role of processing strategy in terms of its effect on structural performances, heat-treatment response, and mechanical behaviour of quasi-crystalline Al–Fe–Cr-based alloy with nominal composition Al94Fe3Cr3. Several kinds of semi-products and bulk-shaped materials, all processed with Al94Fe3Cr3 alloy, have been produced using rapid solidification by melt spinning, powder atomization, hot extrusion, and cold-spraying, respectively. All kinds of semi-products and bulk-shaped materials comprised nanosize quasi-crystalline particles of i-phase, all embedded in α-Al matrix, although fraction volume of quasi-crystals and other structural parameters were rather different and dependent on processing route. In particular, cold-spraying technique was believed to give essential advantage in retaining quasi-crystalline particles contained by feedstock powder as compared to currently employed hot extrusion. Crucial role of nanosize quasi-crystalline particles in structural performances and superior combination of high strength and sufficient ductility of ternary Al–Fe–Cr alloy was justified over evolution of mechanical properties under heating. In this aim, evolution of the structure and mechanical properties of each kind of Al94Fe3Cr3 alloy in response to heat treatment was examined and discussed by considering the classical strengthening mechanisms. A set of mechanical characteristics including microhardness, HV, yield stress, σy, Young’s modulus, E, and plasticity characteristic δH/δA was determined by indentation technique and used in consideration. Strength properties (HV, σy, E) and plasticity characteristic (δH/δA) of cold-sprayed Al94Fe3Cr3 alloy were revealed to be much higher than those provided by currently employed hot extrusion. The important point concerns the fact that cold-sprayed Al94Fe3Cr3 alloy kept almost stable values of mechanical properties at least up to 350 °C, suggesting potential application of this material in engineering practice under intermediate temperature.

Download Full-text

Enhancement of mechanical properties and corrosion resistance of Mg–2Zn–0.5Zr–1.5Dy (mass%) alloy by a combination of heat treatment and hot extrusion

Materials and Corrosion ◽

10.1002/maco.202112755 ◽

2021 ◽

Author(s):

Huan Li ◽

Jiuba Wen ◽

Ya Liu ◽

Junguang He

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Corrosion Resistance ◽

Hot Extrusion ◽

Mechanical Properties And Corrosion

Download Full-text

Relationships among the Microstructure, Mechanical Properties, and Fatigue Behavior in Thin Ti6Al4V

Advances in Materials Science and Engineering ◽

10.1155/2016/7278267 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 13

Author(s):

Y. Fan ◽

W. Tian ◽

Y. Guo ◽

Z. Sun ◽

J. Xu

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Fatigue Strength ◽

Laser Welding ◽

Fracture Strength ◽

Fatigue Behavior ◽

Fatigue Properties ◽

Proof Stress ◽

Martensite Microstructure

The microstructures of Ti6Al4V are complex and strongly affect its mechanical properties and fatigue behavior. This paper investigates the role of microstructure on mechanical and fatigue properties of thin-section Ti6Al4V sheets, with the aim of reviewing the effects of microstructure on fatigue properties where suboptimal microstructures might result following heat treatment of assemblies that may not be suited to further annealing, for example, following laser welding. Samples of Ti6Al4V sheet were subjected to a range of heat treatments, including annealing and water quenching from temperatures ranging from 650°C to 1050°C. Micrographs of these samples were inspected for microstructure, and hardness, 0.2% proof stress, elongation, and fracture strength were measured and attributed back to microstructure. Fractography was used to support the findings from microstructure and mechanical analyses. The strength ranking from high to low for the microstructures of thin Ti6Al4V sheets observed in this study is as follows: acicularα′martensite, Widmanstätten, bimodal, and equiaxed microstructure. The fatigue strength ranking from high to low is as follows: equiaxed, bimodal, Widmanstätten, and acicularα′martensite microstructure.

Download Full-text

A Guide through the Dental Dimethacrylate Polymer Network Structural Characterization and Interpretation of Physico-Mechanical Properties

Materials ◽

10.3390/ma12244057 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4057 ◽

Cited By ~ 11

Author(s):

Izabela Maria Barszczewska-Rybarek

Keyword(s):

Mechanical Properties ◽

Chemical Structure ◽

Structural Parameters ◽

Polymer Network ◽

Polymer Networks ◽

Impact Resistance ◽

Organic Matrices ◽

Dental Restorative

Material characterization by the determination of relationships between structure and properties at different scales is essential for contemporary material engineering. This review article provides a summary of such studies on dimethacrylate polymer networks. These polymers serve as photocuring organic matrices in the composite dental restorative materials. The polymer network structure was discussed from the perspective of the following three aspects: the chemical structure, molecular structure (characterized by the degree of conversion and crosslink density (chemical as well as physical)), and supramolecular structure (characterized by the microgel agglomerate dimensions). Instrumental techniques and methodologies currently used for the determination of particular structural parameters were summarized. The influence of those parameters as well as the role of hydrogen bonding on basic mechanical properties of dimethacrylate polymer networks were finally demonstrated. Mechanical strength, modulus of elasticity, hardness, and impact resistance were discussed. The issue of the relationship between chemical structure and water sorption was also addressed.

Download Full-text

Consolidation and Mechanical Properties of Mechanically Alloyed Al-Mg Powders

MRS Proceedings ◽

10.1557/proc-1128-u05-46 ◽

2008 ◽

Vol 1128 ◽

Author(s):

Mira Sakaliyska ◽

Sergio Scudino ◽

Hoang Viet Nguyen ◽

Kumar Babu Surreddi ◽

Birgit Bartusch ◽

...

Keyword(s):

Mechanical Properties ◽

Sintering Temperature ◽

Nanocrystalline Structure ◽

Hot Extrusion ◽

High Strength ◽

Processing Route ◽

Compression Tests ◽

Mechanically Alloyed ◽

Different Temperatures ◽

Microstructure Density

AbstractNanostructured Al-Mg bulk samples with compositions in the range of 10 – 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al90Mg10 and Al80Mg20 were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al90Mg10 specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al60Mg40 powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.

Download Full-text