scholarly journals Effect of Ti Addition on the Microstructure and Mechanical Properties of SiC Matrix Composites Infiltrated by Al–Si (10 wt.%)–xTi Alloy

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 318
Author(s):  
Yajun Yu ◽  
An Du ◽  
Xue Zhao ◽  
Yongzhe Fan ◽  
Ruina Ma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Intermetallic Compounds ◽  
Bending Strength ◽  
Al Alloys ◽  
Al Alloy ◽  
Matrix Composites ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Ti Addition

This paper proposes a simple reactive melt infiltration process to improve the mechanical properties of silicon carbide (SiC) ceramics. SiC matrix composites were infiltrated by Al–Si (10 wt.%)–xTi melts at 900 °C for 4 h. The effects of Ti addition on the microstructure and mechanical properties of the composites were investigated. The results showed that the three-point bending strength, fracture toughness (by single-edge notched beam test), and fracture toughness (by Vickers indentation method) of the SiC ceramics increased most by 34.3%, 48.5%, and 128.5%, respectively, following an infiltration with the Al–Si (10 wt.%)–Ti (15 wt.%) melt. A distinct white reaction layer mainly containing a Ti3Si(Al)C2 phase was formed on the surface of the composites infiltrated by Al alloys containing Ti. Ti–Al intermetallic compounds were scattered in the inner regions of the composites. With the increase in the Ti content (from 0 to 15 wt.%) in the Al alloy, the relative contents of Ti3Si(Al)C2 and Ti–Al intermetallic compounds increased. Compared with the fabricated composite infiltrated by an Al alloy without Ti, the fabricated composites infiltrated by Al alloys containing Ti showed improved overall mechanical properties owing to formation of higher relative content Ti3Si(Al)C2 phase and small amounts of Ti–Al intermetallic compounds.

Microstructure and Mechanical Properties of Sintered Fibrous Monolith Cemented Carbide

2013 ◽  
Vol 815 ◽  
pp. 233-239
Author(s):  
Xue Quan Liu ◽  
Cun Guang Ding ◽  
Chang Hai Li ◽  
Yi Li ◽  
Li Xin Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Crack Propagation ◽  
Fracture Energy ◽  
Bending Strength ◽  
Extrusion Process ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Microstructure And Mechanical Properties

A fibrous monolith cemented carbide with WC-6Co as cell and WC-20Co as cell boundaries was produced through hot co-extrusion process in this paper. The density, hardness, bending strength and fracture toughness of the fibrous monolith cemented carbide were tested, and the fracture and crack propagation were observed by metalloscope and SEM. The results showed that the bending strength and fracture toughness of the fibrous monolith cemented carbides was remarkably improved 71.91% and 45.7% respectively, while the hardness was slightly decreased 1% compared with WC-6Co composites. It is the reason that the tougher shell WC-20Co with higher bending strength and fracture toughness can absorb more fracture energy, which can slow down and prevent the crack propagating from brittle core WC-6Co.

Effect of Sr Addition on Microstructure and Mechanical Properties of Semi-Solid 2024 Al Alloys

2014 ◽  
Vol 496-500 ◽  
pp. 336-339
Author(s):  
Nisachon Khunbanterng ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Phase Formation ◽  
Al Alloys ◽  
Al Alloy ◽  
Microstructure And Mechanical Properties ◽  
2024 Alloy ◽  
Heat Treated ◽  
Semi Solid

Semi-solid 2024 Al alloys with strontium (Sr) addition of 0.15 wt% and 0.3 wt% were prepared by Gas Induced Semi-Solid (GISS) process. Effect of Sr addition on the microstructure and mechanical properties of the semi-solid 2024 alloy was investigated. It was found that the tensile strength and % elongation of the T6 heat treated alloy with the Sr addition were higher than those without Sr addition owing to the reduction of Mg2Si phase formation. The semi-solid 2024 Al alloy with 0.15%Sr addition obtained the average highest tensile strength of 382 MPa and elongation of 6.45%.

Hot-Press Sintering of Tic0.5N0.5-Based Cermets: Addition Effect of AlN Nano-Powder on Microstructure and Mechanical Properties

2017 ◽  
Vol 726 ◽  
pp. 297-302
Author(s):  
Chang Chun Lv ◽  
Yu Jia Zhai ◽  
Cheng Biao Wang ◽  
Zhi Jian Peng
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Hot Press ◽  
Nano Powder ◽  
Microstructure And Mechanical Properties ◽  
Hot Press Sintering

TiCN-based cermets were prepared by hot-press sintering through adding various amounts of AlN nanopowder (0-20 wt.%) into a 64 wt.% TiC0.5N0.5-10 wt.% WC-8.5 wt.% Mo-12.5 wt.% Ni-5 wt.% Co system. The microstructure and mechanical properties of the prepared cermets were investigated. For the prepared cermets, samples with 5 wt.% AlN nanopowder exhibited optimum mechanical properties of Vickers hardness 2191 HV10, bending strength 601 MPa, and fracture toughness 6.03 MPa.m1/2, respectively.

Effects of Carbon Black on Microstructure and Mechanical Properties of Hot Pressed ZrB2-SiC Ceramics

2010 ◽  
Vol 434-435 ◽  
pp. 185-188 ◽  
Author(s):  
Xin Sun ◽  
Xing Hong Zhang ◽  
Zhi Wang ◽  
Wen Bo Han ◽  
Chang Qing Hong
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Carbon Black ◽  
Potential Method ◽  
Ceramic Composites ◽  
Grain Refining ◽  
Ultra High Temperature Ceramics ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties

Abstract. ZrB2-SiC ultra-high temperature ceramics (UHTCs) was hot-pressed at a temperature of 1900°C with the addition of carbon black as a reinforcing phase. Microstructure and mechanical properties were investigated. Analysis revealed that the amount of carbon black had a significant influence on the sinterability and mechanical properties of ZrB2-SiC ceramics. When a small amount ( < 10 vol.%) of carbon black was introduced, it may react with oxide impurities (i.e. ZrO2, B2O3 and SiO2) present on the surface of the starting powder, thus promote the densification and grain refining of ZrB2-SiC ceramics. As a result, the mechanical properties including flexural strength and fracture toughness were improved. However, with the further adoption of carbon black, mechanical properties were not improved much, which could be attributed to the redundant phase at grain boundaries. The results presented here point to a potential method for improving densification, microstructure and mechanical properties of ZrB2-based ceramic composites.

Microstructure and Mechanical Properties of Heat-Resistant Silicon Carbide Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1409-1413 ◽  
Author(s):  
Young Wook Kim ◽  
Yong Seong Chun ◽  
Sung Hee Lee ◽  
Ji Yeon Park ◽  
Toshiyuki Nishimura ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Silicon Carbide ◽  
Intergranular Phase ◽  
Sintering Additives ◽  
Heat Resistant ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics

There has been a great progress in the development of heat-resistant silicon carbide ceramics, owing to the better understanding of composition-microstructure-properties relations. Based on the progress, it has been possible to fabricate heat-resistant SiC ceramics with improved fracture toughness. In this paper, three rare-earth oxides (Re2O3, Re=Er, Lu, and Sc) in combination with AlN were used as sintering additives for a β-SiC containing 1 vol% α-SiC seeds. The effect of intergranular phase, using Re2O3 and AlN as sintering additives, on the microstructure and mechanical properties of liquid-phasesintered, and subsequently annealed SiC ceramics were investigated. The microstructure and mechanical properties were strongly influenced by the sintering additive composition, which determines the chemistry and structure of IGP. The strength and fracture toughness of the Lu2O3-doped SiC were ∼700 MPa at 1400oC and ∼6 MPa.m1/2 at room temperature, respectively. The beneficial effect of the new additive compositions on high-temperature strength was attributed to the crystallization of the intergranular phase.

Microstructure and Mechanical Properties of Al2O3/ZrO2 Composites Prepared by Gelcasting

2007 ◽  
Vol 280-283 ◽  
pp. 1057-1060
Author(s):  
Bao Xiang Jiao ◽  
Tai Qiu ◽  
Chun Cheng Li ◽  
Chun Ying Shen
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Solid Loading ◽  
Zro2 Content ◽  
Zro2 Particle ◽  
Microstructure And Mechanical Properties ◽  
Dry Pressing ◽  
Gelcasting Process ◽  
Zirconia Toughened Alumina

Microstructure and mechanical properties of zirconia-toughened alumina (ZTA) composite ceramics prepared by gelcasting process were investigated. The results indicated that Al2O3-ZrO2 composites have high bending strength and fracture toughness for the solid loading of the suspension ³ 50vol.%. The bending strength and fracture toughness of sintered ZTA ceramics reach values as high as 631.5 MPa and 7.64 MPa·m1/2, respectively, with solid loading of suspension being 55vol.%. The t-ZrO2 content is increased, and the uniformity of ZrO2 particle distribution is improved in sintered samples prepared by gelcasting compared with those by dry pressing.

Effect of Forming Pressure on Microstructure and Mechanical Properties of B4C- SiC-Si Ceramic Composites

2018 ◽  
Vol 768 ◽  
pp. 152-158 ◽  
Author(s):  
Hui Zong ◽  
Cui Ping Zhang ◽  
Hong Qiang Ru ◽  
He Huang ◽  
Jing Hui Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Ceramic Composites ◽  
Volume Density ◽  
Molten Silicon ◽  
X Ray Diffraction ◽  
Universal Testing ◽  
Microstructure And Mechanical Properties ◽  
Infiltration Method

B4C-SiC-Si ceramic composites were fabricated based on molten silicon infiltration method. The influence of preforms'forming pressure on the microstructure and mechanical properties of B4C-SiC-Si ceramic composites was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron universal testing machines, etc. The results showed that the ceramic consists of B4C, B12(C,Si,B)3, SiC and Si phases. The microstructure analysis showed that: the volume percent of free silicon decreased with the increase in forming pressures. The Vikers-hardness of B4C-SiC-Si ceramic composites increased, while the bending strength and fracture toughness both increased initially and then decreased with the increase in forming pressures of which the optimal pressure is 200 MPa. The optimum bending strength, fracture toughness and Vikers-hardness of the obtained B4C-SiC-Si ceramic composites are 319±13 MPa, 4.9±0.1 MPa·m1/2and 24±1 GPa, respectively. The volume density and open porosity of the obtained B4C-SiC-Si ceramic composites are 2.58 g/cm3and 0.19 %, respectively.

Formation of tough interlocking microstructure in ZrB2–SiC-based ultrahigh-temperature ceramics by pressureless sintering

2009 ◽  
Vol 24 (7) ◽  
pp. 2428-2434 ◽  
Author(s):  
Ji Zou ◽  
Guo-Jun Zhang ◽  
Yan-Mei Kan
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Raw Materials ◽  
Pressureless Sintering ◽  
Sic Ceramics ◽  
Microstructure And Mechanical Properties ◽  
Ultrahigh Temperature

A self-reinforced ultrahigh-temperature ceramic (UHTC) with elongated ZrB2 grains has been successfully densified by pressureless sintering using commercially available ZrB2, SiC, and WC powders as raw materials. Benefiting from the unique interlocking microstructure, this material had improved strength (518 ± 10 MPa) and higher fracture toughness (6.5 ± 0.2 MPa m1/2) compared to ZrB2–SiC ceramics prepared by pressureless sintering. This work provides a new route for tailoring the microstructure and mechanical properties of UHTCs.

Investigation the effect addition of nano Al2O3 on microstructure of Yttria tetragonal Zirconia polycrystalline ceramic

2021 ◽  
Vol 2 (107) ◽  
pp. 49-55
Author(s):  
I.J. Alshaibani
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Great Influence ◽  
Tetragonal Zirconia ◽  
Ceramic Matrix Composites ◽  
Elastic Behavior ◽  
Matrix Composites ◽  
Dispersion Phase ◽  
Microstructure And Mechanical Properties ◽  
Vicker’S Microhardness

Purpose: This research aimed to prepare tetragonal zirconia polycrystals powder by coprecipitation method and study effects of addition of different amounts of nano Al2O3 (1, 2 and 4) wt.% on its microstructure and mechanical properties of (5Y-TZP) composite. Design/methodology/approach: The powder was uniaxial pressed at a pressure of 150 MPa and held for 60 s, and sintered at the 1500°C, held for two hours and then cooling down at 5°C/min to room temperature. Microhardness and fracture toughness tests were utilized to evaluate the mechanical properties of yttria tetragonal zirconia polycrystal composite. The microstructure has been observed using field emission scanning electron microscopy(FESEM). Findings: The results showed an addition of nano Al2O3 has a great influence on hardness and microstructure, the increase in Vicker's microhardness of composite samples with the increase in the nano Al2O3 wt.% and microstructure were characterized with homogeneous zirconia distribution, grain growth destruction with the increasing percentage of nano Al2O3. The most important influence is the enhancing of the densification process as the porosity decreased. The highest hardness and maximum fracture toughness were recorded at 4 wt.% nano Al2O3. Research limitations/implications: Ceramic matrix composites are developed to overcome the brittleness of ZrO2 and the low toughness of alumina by formation, a large difference of elastic behavior between matrix and particles(dispersion phase )which disturbs the stress field as a dislocation comes near a particle. Practical implications: Zirconia has mechanical properties similar to those of stainless steel. Yttria-stabilized tetragonal Zirconia (Y-TZP) is growing used in dentistry due to its good mechanical properties such as hardness and fracture toughness. Thus, controlling of microstructure by adding nanoalumina plays an important role in enhancing these properties. Originality/value: Study the adding bitty percentage from nano alumina on microstructure and mechanical properties of (5Y-TZP) ceramic.

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