scholarly journals Mechanical Properties of Mo2NiB2 Base Hard Alloys and Crystal Structures of Boride Phases

1994 ◽  
Vol 58 (8) ◽  
pp. 959-965 ◽  
Author(s):  
Masao Komai ◽  
Yuji Yamasaki ◽  
Shinya Ozaki ◽  
Ken-ichi Takagi
Keyword(s):  
Mechanical Properties ◽  
Crystal Structures ◽  
Hard Alloys ◽  
Boride Phases

Preparation of WC-TiC-Ni3Al-CaF2 functionally graded self-lubricating tool material by microwave sintering and its cutting performance

2020 ◽  
Vol 39 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Siwen Tang ◽  
Rui Wang ◽  
Pengfei Liu ◽  
Qiulin Niu ◽  
Guoqing Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Microwave Heating ◽  
Cutting Performance ◽  
Conventional Heating ◽  
Hard Alloys ◽  
Dry Cutting ◽  
Temperature Oxidation ◽  
Lubricating Material ◽  
Heating Technology

AbstractWith the concern of the environment, green dry cutting technology is getting more and more attention and self-lubricating tool technology plays an important role in dry cutting. Due to the demand for high temperature performance of tools during dry cutting process, cemented carbide with Ni3Al as the binder phase has received extensive attention due to its excellent high temperature strength and high temperature oxidation resistance. In this paper, WC-TiC-Ni3Al-CaF2 graded self-lubricating material and tools were prepared by microwave heating method, and its microstructure, mechanical properties and cutting performance were studied. Results show that gradient self-lubricating material can be quickly prepared by microwave heating technology, and the strength is equivalent to that of conventional heating technology. CaF2 not only plays a role in self-lubrication, but also refines the grain of the material. A reasonable gradient design can improve the mechanical properties of the material. When the gradient distribution exponent is n1 = 2, the material has high mechanical properties. Cutting experiments show that the WC-TiC-Ni3Al-CaF2 functional gradient self-lubricating tool has better cutting performance than the homogeneous WC-TiC-Ni3Al hard alloys.

scholarly journals The crystal structures and mechanical properties of the uranyl carbonate minerals roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite

2020 ◽  
Vol 7 (21) ◽  
pp. 4197-4221 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Jiří Sejkora
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bonding ◽  
Diffraction Pattern ◽  
Crystal Structures ◽  
First Principles ◽  
X Ray Diffraction ◽  
Carbonate Minerals ◽  
X Ray ◽  
Uranyl Carbonate

The structure, hydrogen bonding, X-ray diffraction pattern and mechanical properties of six important uranyl carbonate minerals, roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite, are determined using first principles methods.

Crystal structures and mechanical properties of tungsten monocarbide predicted by first-principles investigations

2021 ◽  
Vol 130 (19) ◽  
pp. 195902
Author(s):  
Huai-Yong Zhang ◽  
Yun-Dong Guo ◽  
Shuo Min ◽  
Chang-You Ma ◽  
Jian Li
Keyword(s):  
Mechanical Properties ◽  
Crystal Structures ◽  
First Principles ◽  
Tungsten Monocarbide

scholarly journals The Microstructure, Mechanical Properties and Coatability of Diffusion Brazed CMSX-4 Single Crystal

1996 ◽  
Author(s):  
Warren M. Miglietti ◽  
Ros C. Pennefather
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Elevated Temperatures ◽  
Aluminide Coating ◽  
Turbine Blades ◽  
Stress Rupture ◽  
Directionally Solidified ◽  
Diffusion Brazing ◽  
Brazed Joints ◽  
Boride Phases

Diffusion brazing is a joining process utilized both in the manufacture and repair of turbine blades and vanes. CMSX-4 is an investment cast, single crystal, Ni-based superalloy used for turbine blading and vanes, and has enhanced mechanical properties at elevated temperatures when compared to equiaxed, directionally solidified and first generation single crystal superalloys. The objective of this work was to develop a diffusion brazing procedure to achieve reliable joints in the manufacture of a hollow turbine blade (for a prototype engine in South Africa), and to verify the coatability of the diffusion brazed joints. Two commercially available brazing filler metals of composition Ni-15Cr-3.5B and Ni-7Cr-3Fe-4.5Si-3.2B-0.06C and a proprietary (wide gap) braze were utilized. With the aim of eliminating brittle centre-line boride phases, the effects of temperature and time on the joint microstructure were studied. Once the metallurgy of the joint was understood, tensile and stress rupture tests were undertaken, the latter being one of the severest tests to evaluate joint strength. The results demonstrated that the diffusion brazed joints could satisfy the specified stress rupture criterion of a minimum of 40 hrs life at 925 °C and 200 MPa. After mechanical property evaluations, an investigation into the effects of a low temperature high activity (LTHA) pack aluminide coating and a high temperature low activity (HTLA) pack aluminide coating on the braze joints was undertaken. The results showed that diffusion brazed joints could be readily coated.

scholarly journals Chemical Method of Receipt of Powder-Like Mixtures of Copper Crystals (Cu) -Nano, Micro Dispersion of for Reinforcement of Polymeric Compositions are Used as Materials for Printing 3D

2016 ◽  
Vol 17 (2) ◽  
pp. 269-274
Author(s):  
М.V. Gorenko
Keyword(s):  
Mechanical Properties ◽  
Crystal Structures ◽  
Copper Powder ◽  
Chemical Process ◽  
Chemical Method ◽  
Crystallization Process ◽  
Powder Mixtures ◽  
Polymeric Compositions ◽  
Extrusion Method ◽  
Copper Crystals

We consider possibility of the chemical process of obtaining crystals of copper powder mixtures -nano, micro dispersion of for reinforcement of polymeric compositions are used as materials for printing 3D thermo-extrusion method, is given determination the physic and to mechanical properties of the resulting material, depending on the filler, we offer a method to reduce the porosity of products for the SLS technology, DMLS,investigated kinds of crystal structures of copper (Cu) and crystallization process copper (Cu) with -nano phase in solution H2O.

Effect of Ruthenium, Rhenium and Yttria Additions on the Microstructure of Wide Gap Brazing of IN738

2007 ◽  
Author(s):  
Xiao Huang ◽  
Scott Yandt ◽  
Doug Nagy ◽  
Matthew Yao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Life Cycle Cost ◽  
Filler Metal ◽  
Braze Alloy ◽  
Cost Effective ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Wide Gap ◽  
Boride Phases

Modern gas and steam turbine components are subject to severe thermomechanical loads and extremely high temperature in order to provide increased performance and efficiency. Most high temperature turbine components are made of superalloys specifically developed for high temperature and high mechanical stress applications but at considerable cost. Defects may occur during manufacturing of superalloy castings as well as after service. Repair of these components, rather than replacement, helps to reduce the life cycle cost. Wide gap brazing is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. With proper control of the braze alloy and brazing cycle, the repaired region has been reported to posses mechanical properties approaching that of the parent materials. In order to further improve the mechanical properties of the repaired region and to explore the possibility of employing the wide gap brazing method to repair single crystal components in the future, three alloying additions, Ruthenium (Ru), Rhenium (Re) and yttria (Y2O3), were incorporated into the braze filler metal by mechanical alloying. The microstructures of the wide gap brazed joints with Ru, Re and yttria additions were studied and compared to a braze joint with standard wide gap braze alloys of IN738 and AWS BNi-9. It has been found that two types of borides formed in all braze alloys, namely eutectic γ-Ni-rich and boride phases and discrete boride containing primarily Cr and W (or Ru). The addition of Ru to the filler metal did not seem to modify the microstructural constituents after brazing. However, Ru partitioned strongly to the discrete borides. No isolated elemental Ru region was observed. On the other hand, Re addition was found to change the occurrence and distribution of both types of borides. The eutectic boride constituent was significantly reduced and finer discrete boride particles were observed. The addition of yttria did not change the boride formation but led to the generation of more voids in the brazed joint.

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