scholarly journals Characterization of SiC Ceramic Joints Brazed Using Au–Ni–Pd–Ti High-Temperature Filler Alloy

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 931
Author(s):  
Huamin He ◽  
Chuanyang Lu ◽  
Yanming He ◽  
Wenjian Zheng ◽  
Jianguo Yang ◽  
...  
Keyword(s):  
High Temperature ◽  
Reaction Layer ◽  
Thermal Stresses ◽  
Fracture Morphology ◽  
Filler Alloy ◽  
Soaking Time ◽  
Sic Ceramics ◽  
Joint Fracture ◽  
Sic Ceramic

In this work, (Au79Ni17Pd4)96Ti4 (wt.%) filler alloy was designed and employed to join SiC ceramics. The effects of brazing temperature and soaking time on the microstructure and fracture morphology of joints were investigated. The results show that the joint obtained can be described as SiC/reaction layer/braze/reaction layer/SiC. The reaction layer was composed of TiC and Au (Si, Ti). The wettability of the filler alloy toward the SiC ceramics was analyzed. The braze zone was mainly constituted by Pd2Si, Ni2Si, and Au (Ni, Si). A large number of nano-sized TiC particles were distributed within the Au (Ni, Si) layer. The formation mechanism of the braze containing different phases was discussed. The brazing temperature and soaking time had a significant effect on the reaction layer at the SiC/braze interface and TiC particles within the Au (Ni, Si) layer, while they showed a negligible effect on the Pd2Si and Ni2Si within the braze. The inherent reason was also clarified in detail. The joint fractography indicated that a good bonding was achieved between the filler alloy and SiC, while joint fracture was primarily induced by the thermal stresses residing after the brazing cycle.

Joining of SiC Ceramic to Graphite Using Ni-51Cr Powders as Filler

2008 ◽  
Vol 368-372 ◽  
pp. 1600-1602 ◽  
Author(s):  
Yang Wu Mao ◽  
Shu Jie Li ◽  
Lian Sheng Yan
Keyword(s):  
High Temperature ◽  
Chemical Reactions ◽  
Reaction Layer ◽  
Bending Strength ◽  
Weld Zone ◽  
High Strength ◽  
Interfacial Area ◽  
Three Point Bending ◽  
Sic Ceramic ◽  
Points Of View

Joining of SiC ceramic to graphite is important from both technical and economical points of view. High temperature brazing of recrystallized SiC ceramic to high strength graphite has been realized using Ni-51Cr (consisting of Ni + 51wt% Cr powders) powders as filler. The obtained maximum three-point bending strength of joints is 32.3MPa, which is equal to 80.8% of the strength of the graphite. Microstructure and phase analysis reveals that interdiffusions and chemical reactions take place in the weld zone. A reaction layer and an interlayer form in the interfacial area. The reaction layer, of which the thickness is about 60-100μm, is contacted with the SiC ceramic. The interlayer with the thickness of about 200μm exists between the graphite and the reaction layer. The reaction layer is mainly composed of Ni2Si, while the interlayer is mainly composed of Cr23C6 and Ni2Si.

Single-source-precursor Synthesis and High-temperature Behavior of SiC Ceramics Containing Boron

2014 ◽  
Vol 33 (6) ◽  
pp. 563-570 ◽  
Author(s):  
Miaomiao Gui ◽  
Yunhui Fang ◽  
Zhaoju Yu
Keyword(s):  
High Temperature ◽  
Temperature Behavior ◽  
Ceramic Yield ◽  
One Pot ◽  
High Temperature Behavior ◽  
Sic Ceramics ◽  
Sic Ceramic ◽  
Single Source Precursor ◽  
Ceramic Microstructure ◽  
Ft Ir

AbstractIn this paper, a hyperbranched polyborocarbosilane (HPBCS) was prepared by a one-pot synthesis with Cl2Si(CH3)CH2Cl, Cl3SiCH2Cl and BCl3 as the starting materials. The obtained HPBCS was characterized by GPC, FT-IR and NMR, and was confirmed to have hyperbranched structures. The thermal property of the resulting HPBCS was investigated by TGA. The ceramic yield of the HPBCS is about 84% and that of the counterpart hyperbranched hydridopolycarbosilane is only 45%, indicating that the introduction of boron into the preceramic polymer significantly improved the ceramic yield. With the polymer-derived ceramic route, the final ceramics were annealed at 1800 °C in argon atmosphere for 2 h in order to characterize the microstructure and to evaluate the high-temperature behavior. The final ceramic microstructure was studied by XRD and SEM, indicating that the introduction of boron dramatically inhibits SiC crystallization. The boron-containing SiC ceramic shows excellent high-temperature behavior against decomposition and crystallization at 1800 °C.

scholarly journals Synthesis and Characterization of SiC Ceramics for High Temperature Resistant Coatings and Matrix

2006 ◽  
Vol 49 (2) ◽  
pp. 237-241
Author(s):  
Hiroyuki WATANABE ◽  
Satoshi KOBAYASHI ◽  
Manabu FUKUSHIMA ◽  
Shuichi WAKAYAMA
Keyword(s):  
High Temperature ◽  
Synthesis And Characterization ◽  
Sic Ceramics

scholarly journals Effect of Brazing Parameters on the Microstructure and Properties of SiC Ceramic Joint with Zr-Cu Filler Metal

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 93
Author(s):  
Bofang Zhou ◽  
Jinfeng Wang ◽  
Keqin Feng ◽  
Yuchen Cai ◽  
Sitan Chen
Keyword(s):  
Shear Strength ◽  
Reaction Layer ◽  
Shear Test ◽  
Filler Metal ◽  
Interface Reaction ◽  
Fracture Morphology ◽  
Holding Time ◽  
Sic Ceramic ◽  
Maximum Shear Strength ◽  
Joint Reaction

The microstructure and mechanical properties of brazing SiC ceramic with Zr-Cu filler metal under different brazing parameters (brazing temperature, holding time) were investigated. The phase of the joint reaction interface between Zr-Cu filler metal and SiC ceramic was characterized by XRD, the microstructure and fracture morphology of the brazing SiC ceramic joint were analyzed by SEM with EDS, and the strength of the joint was evaluated by compression shear test. The results show that the brazing join between SiC ceramic and Zr-Cu filler metal can be realized at the brazing temperature of 1100 °C~1300 °C, and the main products of interface reaction are ZrC and Zr2Si. The shear strength of the joint increases with the brazing temperature, and reaches the highest at 1200 °C. The thickness of interface reaction layer increases with the increase of holding time at brazing temperature of 1200 °C. Thickness of the interface reaction layer is 2.9 μm when the joint is holding for 20 min, and the maximum shear strength of the corresponding brazed SiC ceramic joint is 57 MPa.

Pressureless Sintering of Ultra-High Temperature ZrB2-SiC Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 1746-1749 ◽  
Author(s):  
Zhi Qiang Cheng ◽  
Chang Ling Zhou ◽  
Ting Yan Tian ◽  
Cheng Gong Sun ◽  
Zhi Hong Shi ◽  
...  
Keyword(s):  
High Temperature ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ablation Rate ◽  
Ultra High Temperature Ceramics ◽  
Sintering Additive ◽  
Sic Ceramics ◽  
Ablation Resistance ◽  
Sic Ceramic ◽  
Ultra High Temperature

ZrB2-SiC ultra-high temperature ceramics (UHTCs) were pressureless sintered with Y2O3-Al2O3 as the sintering additives. The effects of sintering additive and crystallization annealing on the microstructure and properties of ZrB2-SiC UHTCs were investigated. Sintering was activated by producing liquid phase of Y2O3 and Al2O3. The relative density of sintered ZrB2-20wt%SiC ceramic could reach 96% when the content of sintering additive was 6% and the sintering temperature was 1750°C and its bending strength, Vickers hardness, and fracture toughness were 412 MPa, 13 GPa, and 6.0 MPa•m1/2, respectively. The crystallization annealing can result in YAG phase from grain boundary and enhance the high temperature properties of the UHTCs. The UHTCs have excellent ablation resistance at ultra-high temperatures, and a very low ablation rate of 0.0006 mm/s after ablation for 900s at 2800°C.

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