Synthesis of Al2O3/AlB12/Al Composite Ceramic Powders by Pulsed Nd:YAG Laser Igniting Method and a Study of their Mechanical Properties

2010 ◽  
Vol 26-28 ◽  
pp. 919-924
Author(s):  
Kai Jin Huang
Keyword(s):  
Fracture Toughness ◽  
Reaction Mechanism ◽  
Nd:Yag Laser ◽  
Bending Strength ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Ceramic Powders ◽  
Pulsed Nd:Yag Laser ◽  
Al Composite ◽  
Pure Al2o3

Based on the combined toughening principle, pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using pulsed Nd:YAG laser igniting method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 1600°C for 2h under the protection of a N2 atmosphere. XRD and SEM techniques were used to characterize the phases and morphologies of the powders and the ceramics. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by pulsed Nd:YAG laser igniting method because the adiabatic temperature of Al-B2O3 system is more than 1800K. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 525.86MPa and 5.68MPa.m1/2, respectively. These values are 50.25% and 42% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2) due to the reinforcing and toughening in-situ formation of small AlN particles.

Synthesis of Al2O3/AlB12/Al Composite Ceramic Powders by a New Laser-Induction Complex Heating Method and a Study of their Mechanical Properties

2010 ◽  
Vol 29-32 ◽  
pp. 596-601
Author(s):  
Kai Jin Huang ◽  
Li Yan ◽  
Hua Min Kou ◽  
Chang Sheng Xie
Keyword(s):  
Fracture Toughness ◽  
Reaction Mechanism ◽  
Bending Strength ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Ceramic Powders ◽  
Heating Method ◽  
Al Composite ◽  
Laser Induction ◽  
Pure Al2o3

Based on the combined toughening principle, pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using a new laser-induction complex heating method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 1600°C for 2h under the protection of a N2 atmosphere. XRD and SEM techniques were used to characterize the phases and morphologies of the powders and the ceramics. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by this new laser-induction complex heating method because the adiabatic temperature of Al-B2O3 system is more than 1800K. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 551.44MPa and 6.04MPa.m1/2, respectively. These values are 57.55% and 51% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2) due to the reinforcing and toughening in-situ formation of small AlN particles.

Synthesis of Al2O3/AlB12/Al Composite Ceramic Powders by High Frequency Induction Heating Method and a Study of Their Mechanical Properties

2010 ◽  
Vol 139-141 ◽  
pp. 63-66
Author(s):  
Kai Jin Huang ◽  
Chao Dong Tan
Keyword(s):  
Induction Heating ◽  
High Frequency ◽  
Bending Strength ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Ceramic Powders ◽  
Heating Method ◽  
Al Composite ◽  
Pure Al2o3 ◽  
High Frequency Induction

Pure Al2O3/AlB12/Al composite ceramic powders have been synthesized using high frequency induction heating method. This method starts from Al and B2O3 powder mixtures, after which Al2O3/AlB12/AlN composite ceramics were fabricated by hot-press sintering at 16000C for 2h under the protection of a N2 atmosphere. The bending strength and the fracture toughness of the ceramics were measured by the three-point bending method and the indentation fracture method, respectively. The results show that the pure Al2O3/AlB12/Al composite ceramic powders can be successfully synthesized by high frequency induction heating method. Al2O3 and AlB12 phases were formed by the liquid-liquid reaction mechanism and the liquid-solid reaction mechanism, respectively. The bending strength and the fracture toughness of the Al2O3/AlB12/AlN composite ceramics were 549.48MPa and 5.96MPa.m1/2, respectively. These values are 56.99% and 49% greater than those of the pure Al2O3 ceramic (350MPa and 4MPa.m1/2).

scholarly journals B4C-TiB2 Composite Ceramics with Ultra-High Fracture Toughness Fabricated by Spark Plasma Sintering

2020 ◽  
Author(s):  
Xingheng Yan ◽  
Xingui Zhou ◽  
Honglei Wang
Keyword(s):  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
Raw Materials ◽  
Composite Ceramic ◽  
High Fracture Toughness ◽  
Composite Ceramics ◽  
High Fracture ◽  
Plasma Sintering ◽  
Spark Plasma

Abstract B4C-TiB2 composite ceramics with ultra-high fracture toughness were successfully prepared via spark plasma sintering using B4C and 30 vol.% Ti3SiC2 as raw materials at different sintering temperatures. The results show that compared with pure B4C ceramics sintered by SPS, the flexural strength and fracture toughness are significantly improved, especially the fracture toughness has been improved by leaps and bounds. When the sintering temperature is 1900 ℃, the B4C-TiB2 composite ceramic has the best comprehensive mechanical properties: hardness, bending strength and fracture toughness are 27.28 GPa, 405.11 MPa and 18.94 MPa·m1/2, respectively. The main two reasons for the ultra-high fracture toughness are the formation of TiB2 three-dimensional network covering the whole composites, and the existence of lamellar graphite at the grain boundary.

Effects of Nb2O5/La2O3 Synergistic Modification on Phase Composition, Microstructure and Mechanical Properties of Al2O3 Ceramics Prepared by Microwave Sintering

2014 ◽  
Vol 633 ◽  
pp. 49-52
Author(s):  
Yun Long Ai ◽  
Kai Wu ◽  
Xiang Hua Xie ◽  
Bing Liang Liang ◽  
Wen He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Bending Strength ◽  
Microwave Sintering ◽  
Composite Ceramic ◽  
Composite Ceramics ◽  
Comprehensive Properties ◽  
Microstructure And Mechanical Properties

Nb2O5-7.5La2O3-Al2O3 composite ceramics were prepared by microwave sintering. The influence of Nb2O5 and La2O3 proportion on the microstructure and mechanical properties of Al2O3 ceramics was investigated. The results show that when the Nb2O5 content was lower than La2O3, the columnar LaAl11O18 grains were generated by the reaction of La2O3 with Al2O3. When the Nb2O5 content was higher than La2O3, the surplus Nb2O5 induced the formation of columnar Al2O3 grains. The growth of columnar Al2O3 grains were promoted synergistically by LaNbO4 formed in-situ and Nb2O5. The 5Nb2O5-7.5La2O3-Al2O3 composite ceramic exhibited excellent comprehensive properties: ρr=99.3% (relative density), HV=11.2GPa (microhardness), KIC= 6.4MPa·m1/2 (fracture toughness), σ=304.3MPa (bending strength).

Preparation and Characterization of Reaction Sintering B4C/SiC Composite Ceramic

2014 ◽  
Vol 602-603 ◽  
pp. 536-539
Author(s):  
Hai Bin Sun ◽  
Yu Jun Zhang ◽  
Qi Song Li
Keyword(s):  
Fracture Toughness ◽  
High Performance ◽  
Bending Strength ◽  
Carbon Sources ◽  
High Hardness ◽  
High Strength ◽  
Composite Ceramic ◽  
High Fracture Toughness ◽  
Reaction Sintering ◽  
High Fracture

High hardness, high strength, high fracture toughness and low density are required for novel bulletproof materials. B4C/SiC composite ceramic is one of the most potential candidates. In this study, B4C/SiC composite ceramic was prepared by reaction sintering. The influence of B4C content, species and content of carbon, sintering temperature on the mechanical properties of B4C/SiC composite ceramic were studied. A high performance B4C/SiC composite ceramic was sintered at 1750°C for 30 min. Phenolic resin and carbon black were both chosen as carbon sources, whose favorable contents were 10wt%, 5wt%, respectively. The density of sintered bodies reduces with B4C content increases. To some extent, fracture toughness, bending strength improve initially and then deteriorate with the increase of B4C content whose optimal amount is 30wt%. The optimal fracture toughness and bending strength of the B4C/SiC composite ceramic are 5.07MPa·m1/2 and 487MPa, respectively. Meanwhile, the Viker-hardness of the sintered body is 30.2GPa, the density is as low as 2.82g/cm3.

Mechanical Properties of α- and β-SiAlON Composite Ceramics Using β-SiAlON Powder

2008 ◽  
Vol 403 ◽  
pp. 111-114 ◽  
Author(s):  
Kei Asakoshi ◽  
Junichi Tatami ◽  
Katsutoshi Komeya ◽  
Takeshi Meguro ◽  
Masahiro Yokouchi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rare Earth ◽  
Chemical Composition ◽  
Metal Oxides ◽  
Bending Strength ◽  
Rare Earth Oxide ◽  
Composite Ceramics ◽  
Oxide Powders ◽  
Sialon Powder

β-SiAlON powder was used as a raw powder to fabricate α/β-SiAlON composite ceramics with different rare earth elements. The phases present in the sample fabricated from -SiAlON, α-Si3N4, AlN, and rare earth oxide powders were - and -SiAlONs. The composition was dependent on the chemical composition and firing profile. The sample obtained by adding Yb2O3 had a high -SiAlON content. The /-SiAlON composite ceramics had high densit. Their microstructures depended on the used metal oxides, namely, the addition of Nd2O3 and CaCO3 resulted in the elongation of the -SiAlON grains. The bending strength, fracture toughness, and hardness were influenced by the -SiAlON content, amount of elongated grains, and density of the sample.

CRACK-HEALING BEHAVIOR AND BENDING STRENGTH OF Al2O3/SiC COMPOSITE CERAMICS ACCORDING TO THE AMOUNT OF ADDITIVE Y2O3

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2910-2915 ◽  
Author(s):  
KI WOO NAM
Keyword(s):  
High Temperature ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Composite Ceramic ◽  
Crack Healing ◽  
Composite Ceramics ◽  
Strength Recovery ◽  
In Situ Observations ◽  
Healing Temperature

Three Al 2 O 3/ SiC composite ceramics were prepared, which included 1, 3 or 5 wt. % Y 2 O 3, and their high-temperature bending strengths and in-situ crack-healing behaviors examined. A surface elliptical-crack of about 100 µm in diameter was introduces on the specimens using a Vickers hardness indenter. From in-situ observations, the Al 2 O 3/ SiC composite ceramic with 3 wt.% Y 2 O 3 showed superior crack-healing ability than the 1 and 5 wt.% Y 2 O 3 ceramics. The as-cracked specimen with 3 wt.% Y 2 O 3 showed strength recovery on healing for 1 hr at 1473 K in air, which may have been due to the lower crack-healing temperature on the addition of 3 wt.% Y 2 O 3. The heat-resistance limit temperatures of the crack-healed Al 2 O 3/ SiC composite ceramics were 1073, 1373 and 873 K for 1, 3 and 5 wt.% Y 2 O 3, respectively.

scholarly journals Effect of Additive Ti3SiC2 Content on Mechanical Properties of B4C–TiB2 Composites Ceramics Sintered by Spark Plasma Sintering

2020 ◽  
Author(s):  
Xingheng Yan ◽  
Xingui Zhou ◽  
Honglei Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Spark Plasma Sintering ◽  
Bending Strength ◽  
High Fracture Toughness ◽  
Transgranular Fracture ◽  
Composite Ceramics ◽  
High Fracture ◽  
Plasma Sintering ◽  
Spark Plasma

Abstract B4C-TiB2 composite ceramics with ultra-high fracture toughness were successfully prepared via spark plasma sintering at 1900℃ using B4C and Ti3SiC2 as raw materials. The results show that compared with pure B4C ceramics sintered by SPS, the hardness of B4C-TiB2 composite ceramics is decreased, but the flexural strength and fracture toughness are significantly improved, especially the fracture toughness has been improved by leaps and bounds. When the content of Ti3SiC2 is 30vol.%, the B4C-TiB2 composite ceramic has the best comprehensive mechanical properties: hardness, bending strength and fracture toughness are 27.28 GPa, 405.11 MPa and 18.94 MPa·m1/2, respectively. The fracture mode of the B4C-TiB2 composite ceramics is a mixture of transgranular fracture and intergranular fracture. Two main two reasons for the ultra-high fracture toughness are the existence of lamellar graphite at the grain boundary, and the formation of a three-dimensional interpenetrating network covering the whole composite.

Microstructure and Properties of Al2O3-ZrO2(n) Composite Ceramics Prepared by Microwave Sintering

2010 ◽  
Vol 177 ◽  
pp. 364-368
Author(s):  
Wen He ◽  
Yun Long Ai ◽  
Chang Hong Liu ◽  
Jian Ping Zhang ◽  
Jia Yuan Ding
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Bending Strength ◽  
Phase Transfer ◽  
Microwave Sintering ◽  
Abrasive Particle ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Composite Ceramics ◽  
Alumina Matrix

Al2O3-ZrO2(n) composite ceramics were prepared by microwave sintering. The properties and microstructure were investigated, including vickers hardness, fracture toughness, bending strength, wear resistance and heat-shocking resistance. The results show that the properties and microstructure of alumina matrix ceramics are affected by the addition of nano-ZrO2 particles. When the content of ZrO2 is 15vol%, the hardness, fracture toughness and bending strength of the Al2O3-ZrO2 composites reach maximum values 13350MPa, 6.41MPa•m1/2 and 502MPa, respectively. The wear resistance of alumina matrix ceramics are improved only on the condition of adding an appropriate amount of nano-ZrO2. The wear mechanism of the composites are abrasive particle wear and adhesion wear co-existing. The crack propagation rate of Al2O3 matrix ceramics decreases remarkably with the addition of nano-ZrO2 particles. The mechanisms of ZrO2 improving the heat-shocking resistance of alumina matrix ceramics are mainly phase transfer toughening. Nano-ZrO2 particles exist in the intragranular and grain boundary of alumina matrix ceramics, and exist intragranular structures.

Preparation and Characterization of Al2O3/ZrO2 Composite Ceramics

2016 ◽  
Vol 697 ◽  
pp. 372-376 ◽  
Author(s):  
Yin Yan Ju ◽  
Xue Xian Gan ◽  
Jie Guang Song ◽  
Fang Wang ◽  
Wang Nian Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Hydrothermal Method ◽  
Atmospheric Pressure ◽  
Bending Strength ◽  
Raw Material ◽  
Low Temperature Sintering ◽  
Composite Ceramics

Alumina-zirconia (Al2O3-ZrO2) composite ceramics were prepared by means of cross spraying and hydrothermal method under atmospheric pressure with nanometer powders doped with ZrO2 as the raw material. Then, the prepared powders and ceramics were characterized by SEM, XRD and BET methods. The results showed that combining cross spraying with hydrothermal method under atmospheric pressure could improve the dispersity of the ZrO2 composite ceramics nanopowders, while adding Al2O3 accelerated the low temperature sintering for 3Y-ZrO2 and improved the bending strength, fracture toughness and density of ZrO2 composite ceramics. In addition, through optimization the bending strength and fracture toughnessof the obtained ceramic, were 1,150 MPa and 8.2 MPa∙m1/2 respectively.

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