Mechanical Properties of Nano-Crystalline Glaze for Wall Tiles Prepared by Controlling TiO2 Nucleating Agents

2020 ◽  
Vol 12 (4) ◽  
pp. 502-509 ◽  
Author(s):  
Yoorim Rho ◽  
Seunggu Kang ◽  
Jinho Kim ◽  
Kangduk Kim
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Crystallization Temperature ◽  
Surface Hardness ◽  
High Hardness ◽  
Nucleating Agent ◽  
Nano Crystalline ◽  
Heat Treated ◽  
Opaque Glaze ◽  
Degree Of Crystallization

In this paper, TiO2 is substituted as a nucleating agent in opaque glaze to produce nano-crystalline glaze with high hardness. The crystallization mechanism of glaze was calculated by non-isothermal thermal analysis by Differential Thermal Analysis (DTA), and the glaze was heat treated at the crystallization temperature (Tp). In the case of glaze (88G20T), in which TiO2 was substituted by 20 wt% showed surface crystallization behaviors because the Avrami constant (n) was 1.18 and the activation energy (E) values were 747.0 kJ/mol at the crystallization temperature (Tp2). The microstructure of the glazes without heat-treatment showed that phase separation transferred from spinodal to nucleation-growth as TiO2 substitution increased. The size of droplets was nano-sized, below 100 nm. The glazes heated at the crystallization temperature (Tp) and crystal size of several hundred nm to several μm was observed. The surface hardness of the crystalline glaze showed a high hardness of 6.74 GPa and the degree of crystallization was 47.5% at 80G20T after heat treatment at Tp2 (1207 °C).

Hardening of Selective Laser Melted M2 Steel

2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
Cutting Tools ◽  
High Speed Steel ◽  
High Hardness ◽  
Steel Part ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Near Net Shape

Abstract Selective laser melting (SLM) is an additive manufacturing technique that can be used to make the near-net-shape metal parts. M2 is a high-speed steel widely used in cutting tools, which is due to its high hardness of this steel. Conventionally, the hardening heat treatment process, including quenching and tempering, is conducted to achieve the high hardness for M2 wrought parts. It was debated if the hardening is needed for additively manufactured M2 parts. In the present work, the M2 steel part is fabricated by SLM. It is found that the hardness of as-fabricated M2 SLM parts is much lower than the hardened M2 wrought parts. The characterization was conducted including X-ray diffraction (XRD), optical microscopy, Scanning Electron Microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) to investigate the microstructure evolution of as-fabricated, quenched, and tempered M2 SLM part. The M2 wrought part was heat-treated simultaneously with the SLM part for comparison. It was found the hardness of M2 SLM part after heat treatment is increased and comparable to the wrought part. Both quenched and tempered M2 SLM and wrought parts have the same microstructure, while the size of the carbides in the wrought part is larger than that in the SLM part.

High Indentation Resistance of Aluminum Borate Based Glass-Ceramics

2013 ◽  
Vol 545 ◽  
pp. 3-7
Author(s):  
Pat Sooksaen ◽  
Pisud Prasertcharoensuk ◽  
Jiraporn Damnernsawat ◽  
Nimit Pattamawitayanimit
Keyword(s):  
Heat Treatment ◽  
Glass Melting ◽  
Isothermal Holding ◽  
Surface Hardness ◽  
Glass Ceramics ◽  
Isothermal Heat Treatment ◽  
Aluminum Borate ◽  
Holding Period ◽  
Heating And Cooling ◽  
Heat Treated

This study investigated the bulk crystallization of 54B2O3-19SiO2-17Al2O3-5BaO-5MgO (mol%) glass. Melting was carried out at 1500°C for 1 h using a bottom-load electric furnace. The glass melt was cast into a block and annealed at 500°C for 2 h. Isothermal heat treatment was carried out at 1100°C for 2, 4, 8, 16, 32 h to form bulk crystallized glass-ceramics using a heating and cooling rate of 5°C/min. Phases present in the glass-ceramic samples were studied by x-ray diffraction. Crystalline Al4B2O9 and Al18B4O33 were the main phases and the phase stability depended on the isothermal time. Microstructures were observed by a scanning electron microscope. The size of aluminum borate whiskers/rods tend to increase with longer isothermal holding period. The whisker/ rod-like crystals uniformly oriented throughout the microstructure in all heat treated samples. This led to interlocking microstructure and hence an increase in hardness and fracture toughness. Glass-ceramics synthesized at longer heat treatment times resulted in an increase in the surface hardness and shorter path length at the corner of the diamond pyramid-shaped indenter. Glass-ceramics synthesized in this study can be applied as high temperature resistant machinable materials because their microstructures can resist micro-cracking upon indentation.

The Process Study on Laser Heat Treatment for CNC Machine Tool Guide

2010 ◽  
Vol 42 ◽  
pp. 335-338
Author(s):  
Hua Li Su ◽  
Xiao Peng Miao ◽  
Yong Zhang
Keyword(s):  
Heat Treatment ◽  
Machine Tool ◽  
Surface Hardness ◽  
High Hardness ◽  
Hardened Layer ◽  
Numerical Control ◽  
Cnc Machine Tools ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Control Machine Tool

With the continuous development of CNC technology, CNC machine tools run at the higher speed. Cutting force will be greater, which is bound to exacerbate the wear and tear of the machine tool guides. Therefore, new requirements of numerical control machine tool guide surface hardness are proposed. Using Laser surface heat treatment process to scan the guide surface of CNC Machine Tool, the guide can get high hardness hardened layer. After being casted iron HT300 was heat treated by the laser, the microstructure is homogeneous, very fine martensite. Its Surface hardness can get to HV832. The treatment enhances the surface abrasion resistance, scratch-resistant capacity.

Heat Treatment Effect on the Microstructural, Hardness and Tribological Behavior of A105 Medium Carbon Steel

2021 ◽  
Vol 406 ◽  
pp. 419-429
Author(s):  
Amel Gharbi ◽  
Khedidja Bouhamla ◽  
Oualid Ghelloudj ◽  
Chems Eddine Ramoul ◽  
Djamel Berdjane ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
High Hardness ◽  
Medium Carbon Steel ◽  
Low Friction ◽  
Tempered Martensite ◽  
Medium Carbon ◽  
Friction Resistance ◽  
Heat Treated ◽  
Low Wear

The present work is a contribution in investigating the effect of heat treatment on microstructure, hardness and friction wear of A105N steel. Samples of 25x25 mm2 cross-section and 15mm thickness have been prepared from the as-received material and then heat-treated. The samples were austenitized at 1050°C for 60 minutes followed by water quenching, then tempered at 500 and 700°C for 120 minutes. Microstructural changes and their effect on the wear resistance and hardness were investigated according to the applied heat treatments. The main results show that after quenching the structure is mostly composed of quenched martensite, which confers high hardness and friction resistance to the steel. While the tempered structure is composed of tempered martensite and ferrite. As the temperature rises to 700°C, the tempered martensite decreases and is fully transformed to ferrite and cementite. A good wear resistance expressed by a low friction coefficient and a low wear rate is achieved by tempering at 500°C.

The Parameters Affecting Strength Calculation of Gears

2014 ◽  
Vol 635 ◽  
pp. 30-34
Author(s):  
Silvia Medvecká-Beňová ◽  
Peter Frankovský ◽  
Iveta Janeková
Keyword(s):  
Bending Strength ◽  
Surface Hardness ◽  
High Hardness ◽  
Metallurgical Industry ◽  
Strength Calculation ◽  
Gear Teeth ◽  
Transmission Mechanisms ◽  
Heat Treated ◽  
Heat Treated Steel ◽  
Treated Layer

Safety and traffic flow of production facilities also depends upon the reliability of technical security equipment. Gearing in the transmission mechanisms must satisfy the conditions of strength calculation. This calculation consists of checking of the gear teeth on bend and contact. From the stress of gears is show that the basic requirements of the material are high hardness of works surfaces and bending strength. Steels best meet these conditions. Used steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500-650 HBW. The advantage of these materials is the high value of the contact pressure in the tough centre core of the tooth. As a final heat treatment are used surface hardening, cementation and hardening, nitridation and carbo-nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. This paper considers the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load.

The Effect of Lithium on Crystallization and Microstructure of Glass-Ceramics in Soda-Lime Silicate System

2018 ◽  
Vol 283 ◽  
pp. 160-166
Author(s):  
Ekarat Meechoowas ◽  
Benjamon Petchareanmongkol ◽  
Usanee Pantulap ◽  
Kanit Tapasa
Keyword(s):  
Heat Treatment ◽  
Crystallization Temperature ◽  
Glass Ceramics ◽  
Soda Lime ◽  
Nucleating Agent ◽  
Optical Microscope ◽  
Exothermic Peak ◽  
Treatment Temperature ◽  
Raw Material ◽  
Silicate System

This study investigated the crystallization of soda-lime silicate (NCS) system by re-melting soda-lime silicate glass cullet with Al2O3 CaCO3 and Li2O. The Li2O was added as a nucleating agent. The effect of the nucleating agent on crystallization was investigated in order to study the possibility for use as a parent glass for glass-ceramics. Soda-lime silicate cullet was the main raw material and its chemical composition by weight was 68% SiO2 2% Al2O3 9% Na2O 9% K2O 3.5% CaO 2.5% MgO 1.2% TiO2 3% SrO and 2% ZnO. Glass batches with composition (%wt) of (65-x) Cullet:13Al2O3:22CaCO3:x(Li2O) (x = 0, 1, 2, 4, 6 and 8) were melted at 1500°C for 3 hours and annealed at 600°C. All glasses added with Li2O were clear except x = 8. The crystallization was investigated by Differential Scanning Colorimetry technique (DSC). The results exhibited the exothermic peak of crystallization (TpI and TpII). The glasses with added Li2O exhibited decreasing crystallization temperature with increasing Li content. The glasses were heated at temperatures around the crystallization temperature (700, 750 and 800°C). After heat treatment, the crystalline phase in the glasses was determined by X-ray diffraction technique (XRD). The microstructure was investigated by optical microscope and Scanning Electron Microscope (SEM). The phases of Nepheline (Na,K)AlSiO4 and Wollastonite (CaSiO3) were found. The crystallization depended on the heat treatment temperature. The thermal expansion of the glasses was determined by the dilatometric method to indicate the characteristics of the glass-ceramics. In conclusion, Li2O had a strong effect on the crystallization in soda-lime silicate system. The result could be applied for the production of glass-ceramics from soda-lime cullet.

scholarly journals The influence of hardening on the operational properties of soil-cutting tools

2021 ◽  
Vol 1 (2) ◽  
pp. 45-51
Author(s):  
B.A. Markov ◽  
◽  
O.V. Sedykh ◽  
V.V. Bondarenko ◽  
◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cutting Tool ◽  
Cutting Tools ◽  
Surface Hardness ◽  
High Hardness ◽  
Carbon Steels ◽  
Negative Effects ◽  
Noticeable Effect ◽  
Soil Cutting ◽  
Resistant Layer

Today, soil cutting tools are mainly made from carbon steels, which are heat treated to provide high hardness and strength. However, at present, the durability of such a hardened soil-cutting tool of both domestic and foreign manufacturers is far from perfect. One of the reasons for the insufficient resistance to abrasive wear of a soil-cutting tool subjected to hardening by heat treatment may be its heating by frictional force in contact with the soil. As a result of such heating, the steel undergoes additional tempering, which leads to a decrease in the surface hardness of the cutting edge of the tool by almost 2 times - 49-50 HRC to 22-34 HRC, de-pending on the intensity of metal heating. This circumstance was established during metallographic studies of samples cut from the shares of the KB-01 body of the PBS-4 plow. One of the ways to solve this problem is to obtain a wear-resistant layer on the surface of the soil-cutting tool, which is not subject to the negative effects of reheating during operation, for example, from alloyed white cast iron by the method of plasma-powder surfacing. Metallographic studies showed that the deposited layer has a hardness of more than 62 HRC. At the same time, such types of heat treatment as hardening, normalization or annealing do not have a noticeable effect on the hardness of the deposited layer. Metallographic studies of the deposited metal after operation also showed the absence of notice-able changes in its microstructure and hardness. This indicates that reheating from the action of fric-tion forces does not have a significant effect on the properties of a soil-cutting tool strengthened by plasma-powder surfacing, which contributes to an increase in its duration of operation.

Quality Control of Heat-Treated Surface of 20CrMo Steel Transmission Countershaft

2011 ◽  
Vol 199-200 ◽  
pp. 1528-1531
Author(s):  
Hong Mei Wang ◽  
Xiao Juan Wang ◽  
Xiao Chun Ma
Keyword(s):  
Heat Treatment ◽  
Process Parameters ◽  
Surface Hardness ◽  
Reliable Operation ◽  
Soft Zone ◽  
Automotive Transmission ◽  
Heat Treated ◽  
Effective Depth ◽  
Hardened Surface

After heat treatment, the surface hardness and effective depth of hardened layers of automotive transmission countershaft, determines the quality of the part itself as well as the normal and reliable operation of the transmission assembly. The paper analyzes the specific reasons for such problems as soft zone on the hardened surface of transmission countershaft when proceeding with carbonitriding in the controlled atmosphere furnace, a multi-purpose furnace. And with process parameters adjusted, the process parameters of heat treatment are corrected that the soft zone has been eliminated and the quality of parts has been effectively controlled.

scholarly journals Performance characteristics of polylactide-talc composites

2020 ◽  
Vol 3 (2) ◽  
pp. 163-168
Author(s):  
D.S. Katruk ◽  
◽  
Kh.V. Kysil ◽  
B.I. Kulish ◽  
A.S. Masyuk ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Diffusion Process ◽  
Heat Resistance ◽  
Thermophysical Properties ◽  
Surface Hardness ◽  
Additional Heat ◽  
Thermomechanical Characteristics ◽  
Heat Treated

The influence of the filler – talc, its content, additional heat treatment and temperature on the physical-mechanical and thermophysical properties of polylactide materials, in particular on the surface hardness, heat resistance according to Vick and thermomechanical characteristics has been studied. The influence of filler and temperature on the resistance of polylactide materials to the action of the aqueous medium is revealed. The diffusion coefficient of water in polylactide materials and the activation energy of the diffusion process were determined. It was found that the process of water absorption by filled and heat- treated materials based on polylactide is slower and requires more activation energy of the process.

Synthesis of CuFeO2 Powder by Sol-Gel Method

2008 ◽  
Vol 368-372 ◽  
pp. 663-665
Author(s):  
Rui Fen Wu ◽  
Wei Pan ◽  
Shan Liu ◽  
Jian Li
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Sol Gel ◽  
Nitrogen Atmosphere ◽  
Gel Method ◽  
Sol Gel Method ◽  
Powder Precursor ◽  
Treatment Conditions ◽  
Heat Treated

Sol-gel method has been adopted to synthesize CuFeO2 powder. Precursor solutions and heat treatment conditions were studied using thermal analysis and XRD. Pure CuFeO2 was obtained using the prepared sol-gel precursor that heat treated at 950°C for 5 h under nitrogen atmosphere.

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