scholarly journals The Selection of Boron Nitride Circles for Grinding Saponite–Titanium Composites Using Non-Parametric Method

2020 ◽  
Vol 57 (6) ◽  
pp. 53-64
Author(s):  
N.M. Huliieva ◽  
D.O. Somov ◽  
V.V. Pasternak ◽  
L.M. Samchuk ◽  
T.I. Chetverzhuk
Keyword(s):  
Silicon Carbide ◽  
Boron Nitride ◽  
Parametric Method ◽  
Cubic Boron Nitride ◽  
Machine Building ◽  
Abrasive Tools ◽  
Different Grain Size ◽  
Processing Stability ◽  
Selection Of ◽  
Non Parametric

AbstractThe issue of grinding saponite–titanium composites has not been considered in the machine building industry yet. The reason is that the chips are stuck on the working surfaces of abrasive tools made of silicon carbide and electrocorundum. This is due to the high adhesive activity at operating cutting temperatures between the composite and traditional abrasives.The article aims at studying the grinding of saponite–titanium composites using abrasive tools in various cutting modes based on parametric and non-parametric statistical methods.To solve this problem, high porous wheels (HPW) made of cubic boron nitride CBN30 with 100 % concentration on a bond V (K27), a pore-forming KF40, varied grains: B76, B126, B151 (ISO 6106:2013) – and hardness: M and O (ISO 525:2013) were used to grind saponite–titanium composites. Additionally, the Norton wheels from green silicon carbide with a normal porosity 39C (46; 60) K8 VK and with different grain size were tested. Norton wheels provide reduction of roughness height by 1.4–1.5 times in comparison with boron nitride HPW. These are recommended for the finishing grinding stage and HPW CBN30 – the preliminary to reduce the thermal effects on composites. By processing stability, the Norton wheels with grain 46 rank first, and among boron nitride HPW – CBN30 B76 100 OV K27–KF40.

Transfer of Abrasive Material at Grinding a Titanium Alloy with a Wheel of Cubic Boron Nitride

2021 ◽  
Vol 316 ◽  
pp. 521-526
Author(s):  
Vladimir A. Nosenko ◽  
Alexander V. Fetisov ◽  
Semen P. Kuznetsov
Keyword(s):  
Titanium Alloy ◽  
Chemical Composition ◽  
Boron Nitride ◽  
Chemical Elements ◽  
Cubic Boron Nitride ◽  
Water Soluble ◽  
Alloy Surface ◽  
Ceramic Bond ◽  
Abrasive Tools ◽  
Wear Products

The article summarizes the results of the of the titanium alloy surface morphology and chemical composition study after grinding with a wheel of cubic boron nitride on a ceramic bond. The titanium alloy was treated using the method of cut-in grinding in the finishing mode using a synthetic water-soluble lubricant-cooling liquid that does not contain mineral oil. The research was carried out using the FEI Versa 3D LoVac electron microscope. Digital photos of the titanium alloy surface at different magnifications are given. Individual objects’ morphology allows us to identify them as wear products of abrasive tools. The chemical composition of the selected objects was studied by local x-ray spectral analysis. CBN crystals are partially or completely pressed into the treated surface and covered with a layer of the treated material. On the surface of CBN crystals, there are chemical elements that are part of the abrasive tool bond.

Cyclic-Cluster Mindo/3 Computations of The Lattice Constant and Band Structure of Boron Nitride, Diamond and Silicon Carbide

1989 ◽  
Vol 162 ◽  
Author(s):  
Lawrence C. Snyder ◽  
Arthur H. Edwards ◽  
Peter Deak
Keyword(s):  
Silicon Carbide ◽  
Silicon Nitride ◽  
Boron Nitride ◽  
Band Structure ◽  
Lattice Constant ◽  
Cubic Boron Nitride ◽  
Heat Of Formation ◽  
Computational Scheme ◽  
Neglect Of Differential Overlap ◽  
Cyclic Cluster

ABSTRACTWe have employed a 32 atom cyclic-cluster and the Modified Intermediate Neglect of Differential Overlap (MINDO/3) method to compute the lattice constant, band structure, heat of formation and other properties of cubic boron nitride, diamond and silicon nitride. The computational scheme we have employed will permit studies of defects in these materials.

Effect of Ni–Cu substrates on phase selection of hexagonal and cubic boron nitride thin films

2003 ◽  
Vol 216 (1-4) ◽  
pp. 72-77 ◽  
Author(s):  
Shigeo Kotake ◽  
Takaya Hasegawa ◽  
Kazutaka Kamiya ◽  
Yasuyuki Suzuki ◽  
Takami Masui ◽  
...  
Keyword(s):  
Thin Films ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Phase Selection ◽  
Cu Substrates ◽  
Selection Of

scholarly journals Recent Trend of Precipitation and Crop Planning at Rajshahi Region of Bangladesh

2021 ◽  
pp. 28-39
Author(s):  
M. H. Ali ◽  
M. H. Zaman ◽  
M. A. Islam ◽  
P. Biswas ◽  
N. N. Karim ◽  
...  
Keyword(s):  
Recent Trend ◽  
Parametric Method ◽  
Monthly Rainfall ◽  
Agricultural Technology ◽  
Rainfall Trend ◽  
Cropping Patterns ◽  
Increasing Trend ◽  
Selection Of ◽  
Non Parametric

The study was carried out for investigation and analysis of long-term (45 years) monthly rainfall data of Rajshahi from 1975 to 2019 for better selection of crops and agricultural technology in this region of Bangladesh. The rainfall trend was determined using parametric and non-parametric method. Probability analysis of rainfall was performed for estimation of dry, wet, and average year rainfall. The results revealed negative trend of yearly rainfall, but it is statistically insignificant. By non-parametric method, ‘no trend’ was observed for yearly rainfall. Increasing trend of monthly rainfall during March and May and decreasing trend in other months were observed. The rainfall deficit period continued from November to March, and in some instant up to April (rainfall<PET).Total deficit for dry, wet, and average year were found as 488.2 mm, 405.7mm and 426.1mm respectively. By adopting low water-demanding cropping patterns during the deficit period, the withdrawal of groundwater can be minimized.

Kraft lignin/cubic boron nitride hybrid materials as functional components for abrasive tools

2019 ◽  
Vol 122 ◽  
pp. 88-94 ◽  
Author(s):  
Łukasz Klapiszewski ◽  
Artur Jamrozik ◽  
Beata Strzemiecka ◽  
Paulina Jakubowska ◽  
Tadeusz J. Szalaty ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hybrid Materials ◽  
Cubic Boron Nitride ◽  
Kraft Lignin ◽  
Abrasive Tools ◽  
Functional Components

Structural relationships in the synthesis of cubic boron nitride thin films by ion-assisted deposition

1994 ◽  
Vol 52 ◽  
pp. 638-639
Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty
Keyword(s):  
Boron Nitride ◽  
Ion Irradiation ◽  
Cubic Boron Nitride ◽  
Film Stress ◽  
Bonded Phases ◽  
Structural Relationships ◽  
Precursor Material ◽  
Pressure Synthesis ◽  
Microstructure Of The Material

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.

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