Physicochemical method for determining the total volume fraction of carbides in annealed high-speed steels

1991 ◽  
Vol 27 (3) ◽  
pp. 127-132
Author(s):  
F.X. Kayser
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Physicochemical Method ◽  
Total Volume Fraction

Moire Fringes on Precipitates in Quenched and Aged Beryllium

1968 ◽  
Vol 26 ◽  
pp. 426-427
Author(s):  
F. J. Fraikor ◽  
A. W. Brewer
Keyword(s):  
Ternary Phase ◽  
Volume Fraction ◽  
Age Hardening ◽  
Orientation Relationships ◽  
Solute Content ◽  
Moiré Fringes ◽  
Moire Patterns ◽  
Total Volume Fraction ◽  
Diffraction Patterns ◽  
Moiré Patterns

A number of investigators have examined moire patterns on precipitate particles in various age-hardening alloys. For example, Phillips has analyzed moire fringes at cobalt precipitates in copper and Von Heimendahl has reported on moire fringes in the system Al-Au. Recently, we have observed moire patterns on impurity precipitates in beryllium quenched in brine from 1000°C and aged at various temperatures in the range of 500-800°C. This heat treatment of beryllium rolled from vacuum cast ingots produces the precipitation of both an fee ternary phase, AlFeBe4, and an hcp binary phase, FeBe11. However, unlike a typical age-hardening alloy, the solute content of this material is low (less than 1000 ppm of Fe and 600 ppm of Al) and hence the total volume fraction of precipitates is small. Therefore there is some difficulty in distinguishing the precipitates and their orientation relationships with the beryllium matrix since the weak precipitate spots generally do not appear on the diffraction patterns.

scholarly journals Study on the High-Speed Milling Performance of High-Volume Fraction SiCp/Al Composites

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4143
Author(s):  
Youzheng Cui ◽  
Shenrou Gao ◽  
Fengjuan Wang ◽  
Qingming Hu ◽  
Cheng Xu ◽  
...  
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Volume Fraction ◽  
Simulation Analysis ◽  
Cutting Temperature ◽  
High Volume ◽  
Cutting Parameters ◽  
High Volume Fraction ◽  
High Wear Resistance ◽  
Element Analysis

Compared with other materials, high-volume fraction aluminum-based silicon carbide composites (hereinafter referred to as SiCp/Al) have many advantages, including high strength, small change in the expansion coefficient due to temperature, high wear resistance, high corrosion resistance, high fatigue resistance, low density, good dimensional stability, and thermal conductivity. SiCp/Al composites have been widely used in aerospace, ordnance, transportation service, precision instruments, and in many other fields. In this study, the ABAQUS/explicit large-scale finite element analysis platform was used to simulate the milling process of SiCp/Al composites. By changing the parameters of the tool angle, milling depth, and milling speed, the influence of these parameters on the cutting force, cutting temperature, cutting stress, and cutting chips was studied. Optimization of the parameters was based on the above change rules to obtain the best processing combination of parameters. Then, the causes of surface machining defects, such as deep pits, shallow pits, and bulges, were simulated and discussed. Finally, the best cutting parameters obtained through simulation analysis was the tool rake angle γ0 = 5°, tool clearance angle α0 = 5°, corner radius r = 0.4 mm, milling depth ap = 50 mm, and milling speed vc= 300 m/min. The optimal combination of milling parameters provides a theoretical basis for subsequent cutting.

Cutting Temperature and Cutting Forces Investigation Based on the Taguchi Design Method when High-Speed Milling of Titanium Matrix Composites with PCD Tool

2016 ◽  
Vol 836-837 ◽  
pp. 168-174 ◽  
Author(s):  
Ying Fei Ge ◽  
Hai Xiang Huan ◽  
Jiu Hua Xu
Keyword(s):  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Volume Fraction ◽  
Cutting Temperature ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
High Speed Milling ◽  
Radial Depth

High-speed milling tests were performed on vol. (5%-8%) TiCp/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.

Velocity and Volume Fraction Measurements of Granular Flows in a Steep Flume

2021 ◽  
Author(s):  
Luca Sarno ◽  
Maria Nicolina Papa ◽  
Luigi Carleo ◽  
Paolo Villani
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Granular Flows ◽  
Indirect Measurement ◽  
Measuring Instruments ◽  
Second Order Statistics ◽  
Granular Dynamics ◽  
Image Velocimetry ◽  
Near Wall

ABSTRACT Laboratory experiments on granular flows remain essential tools for gaining insight into several aspects of granular dynamics that are inaccessible from field-scale investigations. Here, we report an experimental campaign on steady dry granular flows in a flume with inclination of 35°. Different flow rates are investigated by adjusting an inflow gate, while various kinematic boundary conditions are observed by varying the basal roughness. The flume is instrumented with high-speed cameras and a no-flicker LED lamp to get reliable particle image velocimetry measurements in terms of both time averages and second-order statistics (i.e., granular temperature). The same measuring instruments are also used to obtain concurrent estimations of the solid volume fraction at the sidewall by employing the stochastic-optical method (SOM). This innovative approach uses a measurable quantity, called two-dimensional volume fraction, which is correlated with the near-wall volume fraction and is obtainable from digital images under controlled illumination conditions. The knowledge of this quantity allows the indirect measurement of the near-wall volume fraction thanks to a stochastic transfer function previously obtained from numerical simulations of distributions of randomly dispersed spheres. The combined measurements of velocity and volume fraction allow a better understanding of the flow dynamics and reveal the superposition of different flow regimes along the flow depth, where frictional and collisional mechanisms exhibit varying relative magnitudes.

Mechanical Analysis of Low and High Chromium Steels Used in Hot Strip Work Rolls

2018 ◽  
Vol 279 ◽  
pp. 3-9
Author(s):  
Fethi Benkhenafou ◽  
Ines Fernández Pariente ◽  
F.Javier Belzunce ◽  
Abdelkader Ziadi ◽  
Ming Quan Shi ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
High Speed ◽  
Volume Fraction ◽  
Research Work ◽  
High Speed Steel ◽  
Nodular Cast Iron ◽  
High Chromium ◽  
Eutectic Carbides ◽  
Hot Strip ◽  
Conventional Heat Treatment

Microstructure, hardness and fracture toughness of low and high chromium high speed steel used in hot strip mills and subjected to conventional heat treatment have been examined. The influence of tempering temperatures on the mechanical properties of these products, determined using tensile and fracture toughness tests, was studied in this research work. The developed microstructures have been characterized by XRD, optical microscopy and SEM examinations. Macrohardness and microhardness of the specimens have been evaluated by Vickers indentation technique. The fracture toughness of these products was investigated using the rupture weight on 3 points bending specimens. The plane strain fracture toughness KIc and the fracture strength were measured for each alloy. The shell is high harness high speed steels, and the core is nodular cast iron. It was found that most fracture occurred in the eutectic carbides formed by the high content alloy element, such as Mo,V,Cr, but that for the alloys with a reduced volume fraction of eutectic carbides, a small amount of crack propagation occurred in the austenitic dendrites.

scholarly journals New patterns in high-speed granular flows

2015 ◽  
Vol 769 ◽  
pp. 218-228 ◽  
Author(s):  
Nicolas Brodu ◽  
Renaud Delannay ◽  
Alexandre Valance ◽  
Patrick Richard
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Scaling Law ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Particle Volume ◽  
Rheological Models ◽  
Granular Gas ◽  
Internal Structures

We report on new patterns in high-speed flows of granular materials obtained by means of extensive numerical simulations. These patterns emerge from the destabilization of unidirectional flows upon increase of mass holdup and inclination angle, and are characterized by complex internal structures, including secondary flows, heterogeneous particle volume fraction, symmetry breaking and dynamically maintained order. In particular, we evidenced steady and fully developed ‘supported’ flows, which consist of a dense core surrounded by a highly energetic granular gas. Interestingly, despite their overall diversity, these regimes are shown to obey a scaling law for the mass flow rate as a function of the mass holdup. This unique set of three-dimensional flow regimes raises new challenges for extending the scope of current granular rheological models.

Impact Tests in an Air-Water Mixture

2017 ◽  
Author(s):  
Aboulghit El Malki Alaoui
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Optical Probe ◽  
Test Machine ◽  
Water Mixture ◽  
Air Bubble ◽  
Impact Tests ◽  
Void Fractions ◽  
Shock Test Machine ◽  
The Impact

Experimental impact tests were performed using a shock machine and aerated water by means of an air-bubble generator. High speed shock test machine allows carrying out tests of impact on water (slamming). This machine permits to stabilise velocity with a maximal error equal to 10% during slamming tests. The air volume fraction in the bubble was measured by optical probe technique. The present work is aimed at quantifying the effects of the aeration on the hydrodynamic loads and pressures during the entry of a rigid body at constant speed in an air-water mixture. The impact tests were conducted with a rigid pyramid for an impact velocity equal to 15 m.s−1 and for two average void fractions, 0,46% and 0,84%. The reduction of the impact force and pressure due to aeration has been confirmed by these experiments.

Specifics of Microstructure and Phase Composition of High-Speed Steel R6M5

2013 ◽  
Vol 404 ◽  
pp. 20-24 ◽  
Author(s):  
Маzhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Gaukhar Karipbayeva
Keyword(s):  
Phase Composition ◽  
High Speed ◽  
Volume Fraction ◽  
Electron Backscatter Diffraction ◽  
High Speed Steel ◽  
Spherical Shape ◽  
Xrd Analysis ◽  
Steel R6m5 ◽  
Solid Carbide ◽  
Backscatter Diffraction

In this paper microstructure, morphology, elemental composition, phase composition and crystal structure of the sample steel R6M5 were investigate by using the methods of scanning electron microscopy, electron backscatter diffraction (EBSD) analysis and X-ray diffraction (XRD) analysis. Determined that the microstructure of steel R6M5 after hardening and three-time tempering consists of tempered martensite and solid carbide M6C and MC-type with spherical shape and a diameter of less than 3 μm. Detected that the volume fraction of each carbide amounted to 10.4±0.6% and 2.3±0.4% - for grey and bright carbides, respectively, and that the sizes of bright carbides particles in the microstructure of steel R6M5 are 0.4-4,5 μm, and the sizes of grey carbides particles are 0.5-1.1 μm. XRD analysis showed that the main carbides in the studied steel are carbides М6С and MC, which have complicated the FCC crystal lattice and the Fd3m spatial group. Determined that carbides are uniform and monocrystalline. ESBD analysis with the support of the XRD analysis showed that carbides spherical shape М6С fit to Fe3W3C composition.

scholarly journals High-speed, three-dimensional tomographic laser-induced incandescence imaging of soot volume fraction in turbulent flames

2016 ◽  
Vol 24 (26) ◽  
pp. 29547 ◽  
Author(s):  
Terrence R. Meyer ◽  
Benjamin R. Halls ◽  
Naibo Jiang ◽  
Mikhail N. Slipchenko ◽  
Sukesh Roy ◽  
...  
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Soot Volume Fraction ◽  
Turbulent Flames ◽  
Laser Induced Incandescence

The Research of Spraying SiC/Cu Electronic Packaging Composites

2011 ◽  
Vol 284-286 ◽  
pp. 620-623
Author(s):  
Ming Hu ◽  
Jing Gao ◽  
Yun Long Zhang
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Process Parameters ◽  
Electronic Packaging ◽  
High Speed ◽  
Volume Fraction ◽  
Flame Spraying ◽  
Packaging Materials ◽  
Excellent Performance ◽  
Chemical Plating

The SiC/Cu electronic packaging composites with excellent performance were successfully prepared by the chemical plating copper on the surface of SiC powders and high-speed flame spraying technology. The results showed that the homogeneous dense coated layers can be obtained on the surface of SiC powder by optimizing process parameters. The volume fraction of SiC powders in the composites could significantly increase and figure was beyond 55vol% after spraying Copper. The SiC and Cu were the main phases in the spraying SiC/Cu electronic packaging composite, at the same time Cu2O can be tested as the trace phase. The interface combination properties of SiC/Cu in the hot-pressed samples can obviously improve. The thermal expansion coefficient and thermal conductivity of SiC/Cu electronic packaging composite basic can satisfy the requirements for electronic packaging materials.

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