scholarly journals The Influence of Ni-Added Fe-Based Pre-Alloy on Microstructure Evolution and Lifetime Extension of Diamond Tools

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1427
Author(s):  
Juan Pu ◽  
Yubo Sun ◽  
Weimin Long ◽  
Mingfang Wu ◽  
Dashuang Liu ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Service Life ◽  
Brittle Fracture ◽  
Ductile Fracture ◽  
Microstructure Evolution ◽  
Bending Strength ◽  
Diamond Tools ◽  
Ni Content ◽  
Optimal Value ◽  
The Matrix

Diamond tools were prepared by sintering Fe-Cu-Sn-Zn-Ni pre-alloyed powders and diamonds. The effects of Ni contents in pre-alloyed powders on microstructure evolution of Fe-based matrix, the properties of Fe-based matrix and the service life of diamond tools were investigated. The results showed that adding 3~15 wt.% Ni into the Fe-Cu-Sn-Zn pre-alloyed powders refined the microstructure of the Fe-based matrix and improved its density and hardness gradually. The addition of Ni reduced the loss of low melting liquid phase at a low sintered temperature, thus resulting in a decrease of the pores, an increase of the density and hardness of Fe-based matrix. When the Ni content is less than 9 wt.%, the bending strength of Fe-based matrix and diamond tools, together with the holding force of Fe-based matrix to diamonds increases sharply. They reached up to the optimal value with the Ni content of 9 wt.%. At this sintering powder ratio, the sufficient Fe-Cu-Sn-Zn-Ni liquid phase had a good wettability on the surface of diamonds, thus the optimal performance of sintered matrix and diamond tools was obtained. The service life of diamond tools was prolonged greatly owing to the excellent bonding capacity between matrix and diamonds. Once the Ni content exceeded 9 wt.%, the corresponding value decreased gradually. The fracture morphologies of the matrix changed from the brittle fracture into brittle-ductile fracture, then ductile fracture (with the Ni content of 9 wt.%), brittle-ductile mixed fracture and brittle fracture.

Synthesis and Properties of Al2O3 Nanocomposite Ceramics Toughened by Nano Metallic Particles

2007 ◽  
Vol 280-283 ◽  
pp. 1099-1102 ◽  
Author(s):  
Sidi Gu ◽  
Zhao Qiang Zeng
Keyword(s):  
Flexural Strength ◽  
Grain Boundaries ◽  
Bending Strength ◽  
Composite Ceramics ◽  
Three Point Bending ◽  
Metallic Particles ◽  
Ni Content ◽  
Nickel Particles ◽  
The Matrix ◽  
Fine Nickel

Al2O3/Ni composite ceramics toughened by metallic particles was fabricated by the vacuum reduction of Al2O3 and nickel nitrate (Ni(NO3)2•6H2O) mixed powders at 800-1000° for 2-4h and hot pressed at 1400° ~ 1500°C for 1-2h. Three-point bending strength and facture toughness of the composite were studied. With the increase of Ni content, its flexural strength and facture toughness increases significantly. Microstuctural investigations of the composite revealed that fine nickel particles dispersed homogeneously at the matrix grain boundaries, forming the intergranular nanocomposite.

scholarly journals Microstructure Evolution and Lifetime Extension Mechanism of Sn-Added Fe-Based Pre-Alloy Brazing Coating in Diamond Tools

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 364
Author(s):  
Dashuang Liu ◽  
Weimin Long ◽  
Mingfang Wu ◽  
Kai Qi ◽  
Juan Pu
Keyword(s):  
Grain Size ◽  
Flexural Strength ◽  
Microstructure Evolution ◽  
Hot Pressing ◽  
Alloy Powder ◽  
Bending Strength ◽  
Extension Mechanism ◽  
The Matrix ◽  
Hot Pressing Sintering ◽  
Lifetime Extension

The effect of Sn content added in pre-alloy powder on the microstructure, porosity, hardness and bending strength of hot pressing sintering of a diamond matrix was investigated. The results show that with the increase of Sn content in the pre-alloy powder, a reduction in grain size and porosity as well as an increase in hardness is observed. As a result of the reduction in porosity, the flexural strength increases with the increase in the Sn content in the pre-alloy powder. However, with the increase of Sn content, the bending strength decreases owing to the formation of Cu5.6Sn in the matrix. The properties of the diamond matrix are improved, and the lifetime of the diamond matrix is prolonged when the Sn content is 4 wt.%.

scholarly journals Investigation of the microstructure evolution in TP347HFG austenitic steel at 700°C and its characterization method

2021 ◽  
Vol 40 (1) ◽  
pp. 12-22
Author(s):  
Yuetao Zhang ◽  
Tingbi Yuan ◽  
Yawei Shao ◽  
Xiao Wang
Keyword(s):  
Austenitic Steel ◽  
Aging Time ◽  
Microstructure Evolution ◽  
Precipitate Phase ◽  
Dispersion Strengthening ◽  
Micro Hardness ◽  
Dispersed Particles ◽  
Nonlinear Ultrasonic ◽  
The Matrix ◽  
Solution Strengthening

Abstract This article reports the microstructure evolution in TP347HFG austenitic steel during the aging process. The experiments were carried out at 700°C with different aging time from 500 to 3,650 h. The metallographic results show that the coherent twin and incoherent twin are existed in the original TP347HFG grains, while they gradually vanished with the increase of the aging time. After aging for 500 h, a lot of fine, dispersed particles precipitated from the matrix, but they disappeared after aging for 1,500 h. When the aging time extend to 3,650 h, the precipitates appeared apparently coarse in TP347HFG steel, which include the M23C6 and σ phase; besides, the micro-hardness of TP347HFG also changes during the aging, which was closely related to the effect of dispersion strengthening and solution strengthening. The results of the nonlinear ultrasonic measurement reveal that the β′ of TP347HFG steel was also changed with the aging time. It first increased at 0–500 h, then reduced later, and increased finally at 1,500–3,650 h. The variation of β′ in TP347HFG was influenced by a combined effect of the twin microstructure and the precipitate phase, which indicate that the nonlinear ultrasonic technique can be utilized to characterize the microstructure evolution in TP347HFG.

Ni Content Surface Layer Produced by Laser Surface Treatment on Amorphisable Cu Base Alloy

2010 ◽  
Vol 649 ◽  
pp. 101-106
Author(s):  
Mária Svéda ◽  
Dóra Janovszky ◽  
Kinga Tomolya ◽  
Jenő Sólyom ◽  
Zoltán Kálazi ◽  
...  
Keyword(s):  
Surface Layer ◽  
Surface Treatment ◽  
Laser Cladding ◽  
Base Alloy ◽  
Laser Surface ◽  
Laser Alloying ◽  
Laser Surface Treatment ◽  
Ni Content ◽  
Wide Range ◽  
The Matrix

The aim of our research was to comparatively examine Ni content surface layers on amorphisable Cu base alloy produced by different laser surface treatments. Laser surface treatment (LST) techniques, such as laser surface melting, laser alloying and laser cladding, provide a wide range of interesting solutions for the production of wear and corrosion resistant surfaces. [1,2] With LST techniques, the surface can be: i) coated with a layer of another material by laser cladding, ii) the composition of the matrix can be modified by laser alloying. [3] Two kinds of laser surface treatment technologies were used. In the case of coating-melting technology a Ni content surface layer was first developed by galvanization, and then the Ni content layer was melted together with the matrix. In the case of powder blowing technology Ni3Al powder was blown into the layer melted by laser beam and Argon gas. LST was performed using an impulse mode Nd:YAG laser. The laser power and the interaction time were 2 kW and 20÷60 ms. The characterization of the surface layer microstructure was performed by XRD, scanning electron microscopy and microhardness measurements.

scholarly journals Production of ceramics from coal fly ash

2012 ◽  
Vol 18 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Biljana Angjusheva ◽  
Emilija Fidancevska ◽  
Vojo Jovanov
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Solid State ◽  
Liquid Phase ◽  
Bending Strength ◽  
Coal Fly Ash ◽  
Liquid Phase Sintering ◽  
Heating Rates ◽  
Republic Of Macedonia ◽  
The Subject

Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa) and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min). Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al)(Si,Al)2O6] was formed. Ceramics with optimal properties (porosity 2.96?0.5%, bending strength - 47.01?2 MPa, compressive strength - 170 ?5 MPa) was produced at 1100?C using the heating rate of 10?C/min.

Diamond tool wear monitoring by sensory analysis in milling of absolute black granite

2021 ◽  
pp. 095440542110406
Author(s):  
Sandro Turchetta ◽  
Luca Sorrentino ◽  
Gianluca Parodo
Keyword(s):  
Tool Wear ◽  
Cutting Tools ◽  
Depth Of Cut ◽  
Surface Machining ◽  
Diamond Tools ◽  
The Matrix ◽  
Cutting Force Components ◽  
Force Components ◽  
Natural Stones ◽  
And Performance

Diamond tools suitable for machining operations of natural stones can be divided into two groups: cutting tools, including blades, the circular blades and the wires, and the surface machining ones, involving mills and grinders, that can be of different shapes. For the stone sawing process, the most adopted tool type is the diamond mill, whose duration and performance are influenced by various elements such as: the mineralogical characteristics of the material to be machined; the working conditions such as the depth of cut, the feed rate and the spindle speed; the production process of the diamond segment and the characteristics of both the matrix and the diamond, such as the size, the type and the concentration of the diamonds and the metal bond formulation hardness. This work allows to indirectly assess the wear of sintered diamond tools by signal analysis (in time and frequency domain) of the cutting force components acquired in the process. The results obtained represent a fundamental step for the development of a sensory supervision system capable of assessing the tool wear and hence to modify the process parameters in process, in order to optimize cutting performance and tool life.

Effect of Alternative Materials Added to the Plaster Composition

2014 ◽  
Vol 92 ◽  
pp. 127-132
Author(s):  
Nurcan Seyhan ◽  
Aslı Tayçu ◽  
Mehmet Gula ◽  
Arzu Eker ◽  
Kagan Kayaci ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Service Life ◽  
Scanning Electron Microscope ◽  
Water Absorption ◽  
Bending Strength ◽  
Setting Time ◽  
Glass Beads ◽  
Noticeable Effect ◽  
Alternative Materials ◽  
Scanning Electron

In this study, the effect of alternative additives on the properties spred diameter, setting time, bending strength and water absorption of sanitaryware plaster moulds was investigated. The plaster was partially replaced by the alternative additives such as perlite, diatomite and glass beads. Microstructural features of the resultant compositions were determined by scanning electron microscope (SEM). Finally, represantative moulds were produced and their performance was investigated under industrial conditions. It was observed that perlite and diatomite addition deteriorated the strength of plaster moulds and there was no noticeable effect of these additives on casting performance of the plaster moulds. Morever, the presence of glass beads in plaster decreased weight of the moulds without deterioration of moulds service life.

scholarly journals Influence of the Matrix Grain Size on the Apparent Density and Bending Strength of Sand Cores

2017 ◽  
Vol 17 (1) ◽  
pp. 27-30
Author(s):  
R. Dańko
Keyword(s):  
Grain Size ◽  
Apparent Density ◽  
Bending Strength ◽  
Diffraction Method ◽  
Laser Diffraction ◽  
Grain Sizes ◽  
The Matrix

Abstract The results of investigations of the influence of the matrix grain sizes on properties of cores made by the blowing method are presented in the hereby paper. Five kinds of matrices, differing in grain size compositions, determined by the laser diffraction method in the Analysette 22NanoTec device, were applied in investigations. Individual kinds of matrices were used for making core sands in the Cordis technology. From these sands the shaped elements, for determining the apparent density of compacted sands and their bending strength, were made by the blowing method. The shaped elements (cores) were made at shooting pressures being 3, 4 and 5 atn. The bending strength of samples were determined directly after their preparation and after the storing time of 1 hour.

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