scholarly journals Reaction Layer Analysis of In Situ Reinforced Titanium Composites: Influence of the Starting Material Composition on the Mechanical Properties

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 265
Author(s):  
Isabel Montealegre-Meléndez ◽  
Cristina Arévalo ◽  
Ana M. Beltrán ◽  
Michael Kitzmantel ◽  
Erich Neubauer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reaction Layer ◽  
Processing Parameters ◽  
Starting Material ◽  
Secondary Phases ◽  
Layer Analysis ◽  
The Matrix ◽  
B4c Particles ◽  
Al Powder

This study aims at the analysis of the reaction layer between titanium matrices and reinforcements: B4C particles and/or intermetallic TixAly. Likewise, the importance of these reactions was observed; this was particularly noteworthy as regard coherence with the obtained results and the parameters tested. Accordingly, five starting material compositions were studied under identical processing parameters via inductive hot pressing at 1100 °C for 5 min in vacuum conditions. The results revealed how the intermetallics limited the formation of secondary phases (TiC and TiB) created from the B and C source. In this respect, the percentages of TiB and TiC slightly varied when the intermetallic was included in the matrix as prealloyed particles. On the contrary, if the intermetallics appeared in situ by the addition of Ti-Al powder in the starting blend, their content was lesser. The mechanical properties values and the tribology behaviour might deviate, depending on the percentage of the secondary phases formed and its distribution in the matrix.

The Investigation on Aluminium Alloys Automobile Wheel with Low-Titanium Content Produced by Electrolysis

2005 ◽  
Vol 475-479 ◽  
pp. 317-320 ◽  
Author(s):  
Jing Pei Xie ◽  
Ji Wen Li ◽  
Zhong Xia Liu ◽  
Ai Qin Wang ◽  
Yong Gang Weng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminium Alloys ◽  
Solution Treatment ◽  
A356 Alloy ◽  
Aging Treatment ◽  
Titanium Content ◽  
The Matrix ◽  
Automobile Wheel

The in-situ Ti alloying of aluminium alloys was fulfilled by electrolysis, and the material was made into A356 alloy and used in automobile wheels. The results show that the grains of the A356 alloy was refined and the second dendrites arm was shortened due to the in-situ Ti alloying. Trough 3-hour solution treatment and 2-hour aging treatment for the A356 alloy, the microstructures were homogeneous, and Si particles were spheroid and distribute in the matrix fully. The outstanding mechanical properties with tensile strength (σb≥300Mpa) and elongation values (δ≥10%) have been obtained because the heat treatment was optimized. Compared with the traditional materials, tensile strength and elongation were increased by 7.6~14.1% and 7.4~44.3% respectively. The qualities of the automobile wheels were improved remarkably.

Effect of aluminium content and processing parameters on the microstructure and mechanical properties of laser powder-bed fused magnesium-aluminium (0, 3, 6, 9wt%) powder mixture

2019 ◽  
Vol 25 (4) ◽  
pp. 744-751 ◽  
Author(s):  
Xiaomiao Niu ◽  
Hongyao Shen ◽  
Guanhua Xu ◽  
Linchu Zhang ◽  
Jianzhong Fu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Powder Mixture ◽  
Processing Parameters ◽  
Al Alloy ◽  
Content Type ◽  
Powder Bed ◽  
Al Content ◽  
Microstructure And Mechanical Properties ◽  
Al Powder

Purpose Mg-Al powder mixture was used to manufacture Mg-Al alloy by laser powder bed fusion (LPBF) process. This study aims to investigate the influence of initial Al content and processing parameters on the formability, microstructure and consequent mechanical properties of the laser powder bed fused (LPBFed) component. Design/methodology/approach In this study, Al powder with different weight ratio ranged from 3 to 9 per cent was mixed with pure Mg powder, and the powder mixture was processed using different LPBF parameters. Microstructure and compressive properties of the LPBFed components were examined. Findings It was found that the presence of Al significantly modified the microstructure and improved the mechanical properties of the LPBFed components. Higher volume of ß-Al12Mg17 precipitates was produced at higher initial Al content and higher laser energy density. For this reason, the a-Mg was significantly refined and the compressive strength was improved. The highest yield compressive strength achieved was 279 MPa when using Mg-9 Wt. % Al mixture. Originality/value This work demonstrates that LPBF of Mg-Al powder mixture was a viable way to additively manufacture Mg-Al alloy. Both Al content and processing parameters can be modified to control the microstructure and mechanical properties of the LPBFed components.

Postprocessing method-induced mechanical properties of carbon fiber-reinforced thermoplastic composites

2020 ◽  
pp. 089270572094537
Author(s):  
Van-Tho Hoang ◽  
Bo-Seong Kwon ◽  
Jung-Won Sung ◽  
Hyeon-Seok Choe ◽  
Se-Woon Oh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Processing Parameters ◽  
Thermoplastic Composites ◽  
Void Content ◽  
Fiber Reinforced ◽  
Crystallinity Degree ◽  
Automated Fiber Placement ◽  
Carbon Fiber Reinforced

Promising carbon fiber-reinforced thermoplastic (CF/polyetherketoneketone (PEKK)) composites were fabricated by the state-of-the-art technology known as “Automated Fiber Placement.” The mechanical properties of CF/PEKK were evaluated for four different postprocessing methods: in situ consolidation, annealing, vacuum bag only (VBO), and hot press (HP). The evaluation was performed by narrowing down the relevant processing parameters (temperature and layup speed). Furthermore, the void content and crystallinity of CF/PEKK were measured to determine the effect of these postprocessing processes. The HP process resulted in the best quality with the highest interlaminar shear strength, highest crystallinity degree, and lowest void content. The second most effective method was VBO, and annealing also realized an improvement compared with in situ consolidation. The correlation between the postprocessing method and the void content and crystallinity degree was also discussed.

scholarly journals TEM observation of precipitates and their role to mechanical properties in Ti-5553 alloy heated to some temperatures up to 923 K

2020 ◽  
Vol 321 ◽  
pp. 11035
Author(s):  
E. Sukedai ◽  
E. Aeby-Gautier ◽  
M. Dehmas
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Hardening Mechanism ◽  
Transmission Electron ◽  
The Matrix ◽  
Higher Temperature ◽  
Shearing Mechanism ◽  
Hardness Values ◽  
Measured Hardness

A Ti-5553 specimen was continuously heated to 923 K and simultaneously in-situ HEXRD profiles were taken. In addition, specimens heated at the same rate to several temperatures up to 923 K and further quenched were observed by transmission electron microscopy. Based on both results obtained, transformation sequence was clarified, precipitations of ω-, α”iso- and α-phases were confirmed, and size and density of these precipitates were measured. Hardness values of those specimens were also measured. The hardening mechanism was considered as shearing-mechanism for specimens aged at lower temperatures and by-pass one for specimens aged at higher temperature. An attempt of distinction between α”iso - and α-precipitates was also tried. Both precipitates were in needle-like shape and a possibility was suggested by measuring angles between two needle-shape precipitates on {110} of the matrix and comparing with each other.

scholarly journals Effect of Processing Parameters on the Mechanical Properties of Heavy Section Ductile Iron

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Mohamed Mahmoud Mourad ◽  
Shimaa El-Hadad ◽  
Mervat Mohamed Ibrahim ◽  
Adel Abdelmonem Nofal
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Processing Parameters ◽  
Ductile Cast Iron ◽  
Heavy Section ◽  
The Matrix ◽  
Cast Alloys ◽  
One Step ◽  
Inoculation Procedure ◽  
Inoculation Treatment

The main objective of the current work is to investigate the influence of different inoculation conditions on the microstructure and mechanical properties of heavy section ductile iron (DI) castings. Inoculation treatment was done via one step and double step treatments with different amounts of inoculants. The mechanical properties of the fabricated samples were evaluated. The best inoculation procedure in terms of graphite nodules characteristics and mechanical properties was double inoculation with 0.8% inoculants added at first and 0.2% in the late inoculation step. The presence of Sb in one of the cast alloys controlled the growth of graphite nodules in these heavy section ductile iron castings; however low impact toughness was recorded. The matrix structure of ductile cast iron showed a significant influence not only on the strength and impact properties but also on the fracture mode during testing.

Microstructural Design of Si3N4 Based Ceramics

1992 ◽  
Vol 287 ◽  
Author(s):  
M.J. Hoffmann ◽  
G. Petzow
Keyword(s):  
Mechanical Properties ◽  
Aspect Ratio ◽  
Microstructural Analysis ◽  
Coarse Grained ◽  
Boundary Phase ◽  
Microstructural Development ◽  
High Temperature Strength ◽  
Secondary Phases ◽  
The Matrix ◽  
High Degree

ABSTRACTParameters controlling the size and aspect ratio of elongated Si3N4 grains are discussed, based on the assumption that only pre-existing β-Si3N4 particles of the starting powder grow. Powder mixtures of α-rich and β-rich Si3N4 were prepared In order to study the microstructural development. The resulting microstructures were analyzed by quantitative microstructural analysis determining the distribution of the length and aspect ratio of the Si3N4 grains. Subsequently, the Influence of the sintering conditions on grain growth was analyzed In relation to mechanical properties. A high Weibull modulus and the non-catastrophic failure during thermal shock of coarse-grained materials Is attributed to an R-curve behaviour. Finally, the influence of sintering additives on the mechanical properties was studied. The Importance of phase relationships between the matrix and the grain boundary phase Is discussed for Si3N4 with Yb2O3 additives. It Is demonstrated that the oxygen content of Si3N4 powder must been taken Into account In order to devitrify defined secondary phases and to achieve a high degree of crystallization. A reduction in the amount of additives does not necessarily Improve the properties as high temperature strength and creep data Indicate.

In Situ TiB2 and Al2(Y, Gd) Particles Reinforced Magnesium Matrix Composite with Al-Ti-B Addition

2013 ◽  
Vol 312 ◽  
pp. 315-318 ◽  
Author(s):  
C.F. Fang ◽  
L.G. Meng ◽  
N.N. Wu ◽  
X.G. Zhang
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Matrix Alloy ◽  
Tensile Tests ◽  
Solidification Structure ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Reinforced Composite ◽  
The Matrix

In-situ micro/nanosized TiB2 and Al2(Y, Gd) particles reinforced magnesium matrix composite was successfully fabricated by addition of Al-Ti-B preform into Mg-Gd-Y-Zn matrix alloy, its microstructures and properties were investigated. The results show that the introduction of Al-Ti-B preform causes the precipitation of Al2(Y, Gd) particles and the SHS synthesis of TiB2 particles which significantly refine solidification structure. The reinforced Al2(Y, Gd) particles with average sizes of 5-8 μm are uniformly distributed throughout the magnesium matrix, and have a good bond to the matrix. Tensile tests indicate that, compared with the former matrix alloy, mechanical properties of the multiple in-situ particles reinforced composite are improved all-roundly.

PLA-Based Biodegradable Copolyester Nanocomposites: Preparation, Characterization and Mechanical Properties

2011 ◽  
Vol 380 ◽  
pp. 290-293
Author(s):  
Bing Tao Wang ◽  
Ping Zhang ◽  
De Gao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Interfacial Adhesion ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Elongation At Break ◽  
Butylene Terephthalate ◽  
The Matrix ◽  
Different Characteristics

In situ melt copolycondensation was proposed to prepare biodegradable copolyester nanocomposites based on degradable components poly(L-lactic acid) (PLA), rigid segments poly(butylene terephthalate) (PBT), and nanoparticles polyhedral oligomeric silsesquioxanes (POSS). The morphologies and dispersions of two POSS nanoparticles (POSS-NH2 and POSS-PEG) in the copolyester PLABT matrix and their effects on the mechanical properties were investigated. The results demonstrated that the morphologies and dispersions of POSS-NH2 and POSS-PEG showed quite different characteristics. POSS-PEG took better dispersion in the PLABT, while POSS-NH2 had poor dispersions and formed crystalline microaggregates. Due to the good dispersion and strong interfacial adhesion of POSS-PEG with the matrix, the tensile strength and Young’s modulus were greatly improved from 6.4 and 9.6 MPa for neat PLABT up to 11.2 and 70.7 MPa for PLABT/POSS-PEG nanocomposite. Moreover, the incorporation of POSS-PEG could impart macromolecular chains good flexibility and improve the mobility of the chains, so the the elongation at break of PLABT/POSS-PEG nanocomposite dramatically increased from 190 to 350 % compared with neat PLABT.

Study on Microstructure of Laser In Situ Formation of TiBX and TiC Titanium Composite Coatings

2011 ◽  
Vol 686 ◽  
pp. 646-653 ◽  
Author(s):  
Jing Liang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Feng Hua Liu
Keyword(s):  
Laser Cladding ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Pulse Frequency ◽  
Hexagonal Prism ◽  
Disperse Particles ◽  
The Matrix ◽  
Cladding Layers

Two kinds of mixed powders:Ti-6Al-4V/B/C and Ti-6Al-4V/B4C which are pre-pasted or synchronized fed on Ti-6Al-4V substrates separately were scanned by a 500W pulsed YAG laser to induce in situ formation of titanium composite coatings contained TiBxand TiC ceramic reinforced phases. The influences of laser processing parameters including Pulse Frequency (PF), Pulse Width (PW), Laser Power (P) and Scanning Speed (V) together with the powder proportions on the microstructure and properties of the coatings were investigated. Microstructures, phase components of the coating were analyzed by OM, SEM, TEM and XRD respectively. Experimental results show that two and more kinds of ceramic reinforcements were in situ formatted in the matrix of Ti-6Al-4V. TiB and TiC ceramics were formed evenly with the morphology of needle, tiny dendrites and disperse particles in the prepasted single path specimens. For the powder feed laser cladding layers, the ceramic reinforcements were TiB (needlelike), TiB2(hexagonal prism or rodlike), a small amount of TiC (disperse particles) and non fully reacted B4C. The microhardness increased with the increase of the amount of B4C and B+C additions. When the added B and C contents are the same, the microhardness of the coating with B4C addition is higher than that of the coating with B+C addition. The average micro-hardness of a powder prepasted (with 20 wt.% B4C addition) multi-path laser cladding layer formed under the optimized processing parameters is up to 800HV, which is more than 2 times of that of the substrate (340Hv), and the wear weight loss of the layer decreased nearly 3 times that of the substrate.

Synthesis, Microstructure, and Mechanical Properties of FeCo-VC Composites

2006 ◽  
Vol 980 ◽  
Author(s):  
Hongbin Bei ◽  
E. P. George
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Directionally Solidified ◽  
Quaternary Alloys ◽  
The Matrix ◽  
Solid Solution Matrix ◽  
Solution Matrix

AbstractFe-Co-V-C quaternary alloys were drop cast and directionally solidified to obtain an in situ composite. It is found that the fully eutectic structure occurs at a composition of Fe - 40.5Co -10.4V- 8.6C (at. %) in a drop-cast alloy. Directional solidification of this composition in a high-temperature optical floating zone furnace produces a well-aligned microstructure, consisting of sub-micron VC fibers (~19% by volume) embedded in a FeCo-5V solid solution matrix containing ~ 1% C. The temperature dependencies of mechanical properties of this composite were examined by tensile tests and the composite was found to have higher yield strength and lower ductility than the matrix.

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