Study on High Pressure Sintering of Nanocrystalline Diamond with Nano Silicon as Additives

2016 ◽  
Vol 848 ◽  
pp. 613-617
Author(s):  
Fu Ming Deng ◽  
Chang Zhan ◽  
Ye Zhao ◽  
Wen Li Deng ◽  
Qing Lei
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Performance ◽  
Nanocrystalline Diamond ◽  
Hardness Tester ◽  
Sintering Time ◽  
Wear Ratio ◽  
Average Grain Size ◽  
High Pressure Sintering ◽  
Surface Graphitization

In this paper, nanocrystalline diamond with the average grain size of 50nm was prepared under different sintering pressure, temperature and sintering time. The microstructure of the sample was analyzed by SEM, EDS and XRD, and the mechanical properties tested by micro-hardness tester and wear ratio instrument. The results show that the sample sintered under the optimum conditions of oil pressure 87MPa, heating power 4000W and sintering time 120s possessed hardness of 706.41HV and wear ratio of 3280. It indicated that high performance n-PCD sintered from nanodiamond and silicon system can be formed hardly with diamond to diamond bonding but can be formed with diamond to silicon carbide bonding. The poor mechanical properties of the samples were due to the surface adsorption groups and surface graphitization of nanodiamond during high pressure sintering.

Highly Dense Amorphous Si2 BC3 N Monoliths with Excellent Mechanical Properties Prepared by High Pressure Sintering

2015 ◽  
Vol 98 (12) ◽  
pp. 3782-3787 ◽  
Author(s):  
Bin Liang ◽  
Zhihua Yang ◽  
Jiancun Rao ◽  
Delong Cai ◽  
Xiaoming Duan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
High Pressure Sintering

Variation of Microstructure and Mechanical Properties of ZW61 Magnesium Alloy Solidified under Different Pressures

2022 ◽  
Vol 327 ◽  
pp. 3-10
Author(s):  
Shu Sen Wu ◽  
Xiao Gang Fang ◽  
Shu Lin Lü ◽  
Long Fei Liu ◽  
Wei Guo
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Volume Fraction ◽  
Applied Pressure ◽  
Second Phase ◽  
Cast State ◽  
Microstructure And Properties ◽  
Microstructure Refinement ◽  
Porosity Reduction ◽  
Average Grain Size

There is little datum related to microstructure and properties of Mg alloys squeeze-casted with pressure over 200 MPa. In this study, the microstructure and properties of Mg-6Zn-1.4Y (ZW61) alloy solidified under 100MPa to 800MPa were investigated. The results show that a remarkable microstructure refinement and porosity reduction can be reached through solidification under high pressure. The average grain size and the volume fraction of second phase, i.e. quasicrystal I-phase, decrease continuously with the increase of applied pressure. The tensile properties, especially elongation, are obvious enhanced because of the microstructure refinement and castings densification under high pressure. The ultimate tensile strength and elongation of ZW61 alloy in as-cast state are 243 MPa and 18.7% when the applied pressure is 800 MPa, which are increased by 35% and 118% respectively, compared with that of the gravity castings.

Effect of High-Pressure Solution Temperature on Microstructure and Mechanical Properties of AZ61 Magnesium Alloy

2012 ◽  
Vol 580 ◽  
pp. 505-508 ◽  
Author(s):  
Yu Shan Li
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Magnesium Alloy ◽  
Atmospheric Temperature ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Hardness Tester ◽  
Az61 Magnesium Alloy ◽  
Mg17al12 Phase ◽  
Different Temperatures

As-cast AZ61 magnesium alloy was treated by solution under a high-pressure of 3 Gpa at different temperatures, atmospheric temperature, 200, 400, 600, 800 and 1000 °C. The microstructure of the products was observed by optical microscope. The mechanical properties of the products were investigated by brinell hardness tester and tensile testing. The results show that increasing solution temperature promotes the dissolution into α-Mg matrix of β-Mg17Al12 phase of AZ61 alloy, especially for over 400 °C. With increasing solution temperature, the tensile strength and elongation percentage of AZ61 increase gradually, but the hardness decreases.

scholarly journals Mechanical Characterization of Rapid Solidified Alsicumg Alloys by New CRSS Casting Method Under T6 Condition

2019 ◽  
Vol 8 (12) ◽  
pp. 2897-2902
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Process ◽  
High Performance ◽  
Weight Ratio ◽  
Solidification Process ◽  
Casting Process ◽  
Casting Method ◽  
Silicon Alloys ◽  
Hardness Tester

Aluminum-silicon alloys acquiring extensive industrial attention due to their superior resistance to rate of wear and elevated strength to weight ratio properties. Though the properties of the materials substantially depend on the manufacturing process they involve. Thus many industries focusing on new manufacturing methods to produce high-performance alloys. In this present study, AlSi (16-18) alloys were prepared by new CRSS (combined rheo stir squeeze) casting method with rapid-solidification process under T-6 condition. CRSS-T6 as casting process enhances the microstructural and mechanical properties significantly by 40-70%. Whereas, the maximum value of hardness (179.37) was found with AlSi17Cu3.5Mg0.8 with CRSS-T6. The improvements in hardness and elastic properties were mainly ascribed to size, distribution, and morphology of Si-particles because of its manufacturing process. SEM, advanced metallurgical microstructure and EDS analysis techniques are used for the surface morphologies observation. Moreover, Brinell hardness tester and Tensometer are used for the characterization of mechanical properties

Assessment of Mechanical Properties and Transformation Behavior of Locally-Made Ni-Ti Alloys Used in Orthodontics

2008 ◽  
Vol 55-57 ◽  
pp. 245-248 ◽  
Author(s):  
Nattiree Chiranavanit ◽  
Anak Khantachawana ◽  
N. Anuwongnukroh ◽  
Surachai Dechkunakorn
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Testing Machine ◽  
Optical Microscope ◽  
Treatment Temperature ◽  
Bending Test ◽  
Hardness Tester ◽  
Ti Alloys ◽  
Heat Treated ◽  
Average Grain Size

Ni-Ti alloy wires have been widely used in clinical orthodontics because of their properties of superelasticity (SE) and shape memory effect (SME). The purpose of this study was to assess the mechanical properties and phase transformation of 50.7Ni-49.3 Ti (at%) alloy (NT) and 45.2Ni-49.8Ti-5.0Cu (at%) alloy (NTC), cold-rolled with various percent reductions. To investigate SE and SME, heat-treatment was performed at 400°C and 600°C for 1 h. The specimens were examined using an Energy-Dispersive X-ray Spectroscope (EDS), Differential Scanning Calorimeter (DSC), Universal Testing Machine (Instron), Vickers Hardness Tester and Optical Microscope (OM). On the three-point bending test, the superelastic load-deflection curve was seen in NTC heat-treated at 400°C. Furthermore, NT heat-treated at 400°C with 30% reduction produced a partial superelastic curve. For SME, no conditions revealed superelasticity at the oral temperature. Micro-hardness value increased with greater percentage reduction. The average grain size for all specimens was typically 55-80 µm. The results showed that locally-made Ni-Ti alloys have various transformation behaviors and mechanical properties depending on three principal factors: chemical composition, work-hardening (the percent reduction) and heat-treatment temperature.

scholarly journals Microstructure and Properties of AA6061/SiCp Composites Sintered under Ultra High-Pressure

2020 ◽  
Vol 10 (20) ◽  
pp. 7363
Author(s):  
Lei Xu ◽  
Erkuo Yang ◽  
Yasong Wang ◽  
Changyun Li ◽  
Zhiru Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Wear Resistance ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Wear Property ◽  
Ultra High Pressure ◽  
High Pressure Sintering

Ultra high-pressure sintering (UHPS) was used to prepare AA6061/SiCp composites with different contents and the effect of sintering temperatures on microstructure and mechanical properties was investigated in this study. The results showed that a uniform distribution of nano-SiC particles (N-SiCp) is obtained by the UHPS method. With the increase in N-SiCp contents, the higher hardness and better wear resistance could be inspected. The interfacial reactions and Al4C3 phase appeared above 550 °C. The relative density of composites first increased and then decreased; with the temperature raising it reached 99.58% at 600 °C. The hardness and wear property showed the same trend with the hardness reaching 52 HRA and wear rate being 1.0 × 10−6 g/m at 600 °C. Besides, the wear mechanism of the composites is mainly composed of abrasive wear and adhesive wear.

Phase Formation, Microstructures and Mechanical Properties of Lead-Free BNKT Ferroelectric Ceramics Doped with BZZ

2016 ◽  
Vol 675-676 ◽  
pp. 589-592 ◽  
Author(s):  
Chatchai Kruae-In ◽  
Paponsan Puanpia ◽  
Orawan Takhan ◽  
Suchittra Inthong
Keyword(s):  
Mechanical Properties ◽  
Phase Formation ◽  
Xrd Analysis ◽  
Ferroelectric Ceramics ◽  
Sodium Potassium ◽  
Hardness Tester ◽  
Average Grain Size ◽  
All Ceramic ◽  
Pure Phase ◽  
Bismuth Sodium Potassium Titanate

In this research, the effects of bismuth zinc zirconate (BZZ) additive on phase formation, microstructural and mechanical properties of bismuth sodium potassium titanate (BNKT) ceramics were investigated. The BZZ-doped BNKT ceramics were prepared using solid state reaction technique. The pure phase of BZZ-doped BNKT powders were achieved for a calcinations temperature of 850 °C for 4h. The obtained powders were pressed into small pellets and sintered at optimum temperature to from dense ceramics. The XRD analysis of the ceramics shows that all ceramic samples exhibited a pure phase perovskite structure. The bulk densities of samples were about 5.82-6.03 g/cm3 which measured using the Archimedes method. The mechanical properties were measured using micro hardness tester. The microstructural of sintered surface was investigated using scanning electron microscopy (SEM). Average grain size increased with increasing BZZ content. The relations of these results were discussed and compared to the previous works.

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