scholarly journals Tribological behavior, mechanical properties and microstructure of Al-12Si-ZrC composite prepared by powder metallurgy

2017 ◽  
Vol 65 (2) ◽  
pp. 149-154 ◽  
Author(s):  
C. F. John ◽  
R. C. Paul ◽  
S. C. E. Singh ◽  
T. Ramkumar
Keyword(s):  
Testing Machine ◽  
High Energy ◽  
Wear Testing ◽  
Wear Loss ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reinforcement Content ◽  
Gas Atmosphere ◽  
Pin On Disc ◽  
Xrd Techniques

Abstract High-energy mechanical alloying method was used to prepare Al-12Si-xZrC (x = 0, 5, 10, 15 wt. %) nanocomposites. Cylindrical preforms were prepared with an initial preform density of 89% by using a suitable die and punch assembly. The preforms were sintered in a muffle furnace with an inert gas atmosphere at a temperature of 550°C, followed by cooling until room temperature has been attained. Scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques were used to characterize the composites. Pin-on-disc wear testing machine was used to determine the tribological properties of the prepared composites. The results show that the wear loss reduced with increasing the reinforcement content and coefficient of friction increases gradually.

scholarly journals WEAR CHARACTERIZATION OF LM29 ALLOY WITH40 MICRON SIZED B4C REINFORCED METAL COMPOSITES

2021 ◽  
Vol 9 (11) ◽  
pp. 363-371
Author(s):  
G. Pathalinga Prasad ◽  
◽  
H.C. Chittappa ◽  
Madeva Nagaral ◽  
◽  
...  
Keyword(s):  
Normal Load ◽  
Testing Machine ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Wear Testing ◽  
Wear Loss ◽  
Wear Properties ◽  
Alloy Matrix ◽  
Pin On Disc ◽  
B4c Particles

This paper deals with the fabrication and evaluation of wear properties by introducing40 micron size B4C particulates into LM29 alloy matrix. LM29 alloy based metal matrix composites were prepared by stir casting method. 3, 6 and 9 wt. % of 40 micron sized B4C particulates were added to the base matrix. For each composite, the reinforcement particles were pre-heated to a temperature of 600 degree Celsius and then dispersed in steps of two into the vortex of molten LM29 alloy to improve wettability. The Micostructural study was done by using Scanning Electron Microscope (SEM), which revealed the uniform distribution of B4C particles in matrix alloy, EDS analysis confirmed the presence of B4C particles in the LM29 alloy matrix.A pin-on-disc wear testing machine was used to evaluate the wear loss of prepared specimens, in which a hardened EN32 steel disc was used as the counter face. The results revealed that the wear loss was increased with increase in normal load and sliding speed for all the specimens. The results also indicated that the wear loss of the LM29-B4C composites were lesser than that of the LM29 matrix. The worn surfaces and wear debris were characterized by SEM microanalysis.

Influence of Heat-Treatment on High-Phosphorus Ni–P Plating Coating

2011 ◽  
Vol 337 ◽  
pp. 87-90 ◽  
Author(s):  
Xiao Juan Wu ◽  
Zheng Jun Liu ◽  
Guo De Li
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Testing Machine ◽  
Wear Testing ◽  
Thermal Shock Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
High Phosphorus ◽  
Electroless Ni

The high-phosphorus electroless Ni–P plating coating with 11.64 at.% was prepared by electroless technology. By means of x-ray diffraction and scanning electron microscopy, the morphologies and phase structures of coating were analyzed. Furthermore, the mechanical properties of coating were studied by micro-hardness tester and universal friction-wear testing machine. The results reveal that, with increasing heat-treatment temperatures, the hardness and the wear resistance of the coating are enhanced increasingly. Treated by 1 hour at 500 oC, the hardness and the wear resistance both display a optimum value, i.e. 1004 HV and 1.5×10-3g, respectively. The thermal shock test suggests that between coating and matrix exist a perfect cohesion.

Effect of Cladding Current on the Properties of Ti (CN) Ceramic Coating

2013 ◽  
Vol 341-342 ◽  
pp. 79-82
Author(s):  
Li Zhang ◽  
Jian Jun Hao ◽  
Jun Hai Ren ◽  
Jian Chang Li ◽  
Yue Jin Ma
Keyword(s):  
Theoretical Basis ◽  
Ceramic Coating ◽  
Testing Machine ◽  
Graphite Powder ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
X Ray ◽  
Friction Testing ◽  
Gas Atmosphere

In order to study the properties of Ti (CN) ceramic coating, nitrogen arc cladding technology was carried out using TXII500 argon arc cladding machine in nitrogen gas atmosphere, and TiCN based composite coating was preparated on the Q235B specimen surface which is precoated titanium powder and graphite powder. The molten coating was tudied under the cladding current respectively in 200 A, 220 A and 240A. The microstructure, phase composition, micro hardness and wear resistance were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), microhardness tester and reciprocating friction testing machine. The results show that the generation of the Ti (CN) phase is the most when the cladding current is 200A, The microscopic hardness of the coating is reduced with the increase of current, which provides a theoretical basis for the optimization of the process further.

Effects of Additives on the Surface Layers of Boronized TC4 Titanium Alloys

2014 ◽  
Vol 887-888 ◽  
pp. 384-387 ◽  
Author(s):  
Li Na Wang ◽  
Feng Hua Li ◽  
Meng Ge Dong ◽  
Ying Nan Li
Keyword(s):  
Electron Microscopy ◽  
Titanium Alloys ◽  
Friction And Wear ◽  
Testing Machine ◽  
Boride Layer ◽  
Wear Testing ◽  
X Ray Diffraction ◽  
Surface Layers ◽  
X Ray ◽  
Scanning Electron

The boronizing experiments on the surface of Ti-6Al-4V (TC4) titanium alloys were based on solid powder method. Different additives were added into the boronizing agent. The morphologies of surface layers on titanium alloys were observed in scanning electron microscopy (SEM). The phase compositions of boronized layers were analyzed by X-ray diffraction (XRD). The wear resistance properties of boronized TC4 were determined by the friction and wear testing machine. The results showed that all the boronized layers were composed of TiB2and TiB dual phases.When 5%Fe3O4was added into the boronizing agent, the boride layer contained more TiB2compound and was thicker than those with the addition of 5%Na2B4O7.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

scholarly journals In-Situ High-Energy X-ray Diffraction Study of Austenite Decomposition During Rapid Cooling and Isothermal Holding in Two HSLA Steels

2021 ◽  
Vol 52 (5) ◽  
pp. 1812-1825
Author(s):  
Sen Lin ◽  
Ulrika Borggren ◽  
Andreas Stark ◽  
Annika Borgenstam ◽  
Wangzhong Mu ◽  
...  
Keyword(s):  
Isothermal Holding ◽  
Weight Percent ◽  
High Energy ◽  
Decomposition Kinetics ◽  
Bainitic Transformation ◽  
Austenite Decomposition ◽  
X Ray Diffraction ◽  
Rapid Cooling ◽  
X Ray

AbstractIn-situ high-energy X-ray diffraction experiments with high temporal resolution during rapid cooling (280 °C s−1) and isothermal heat treatments (at 450 °C, 500 °C, and 550 °C for 30 minutes) were performed to study austenite decomposition in two commercial high-strength low-alloy steels. The rapid phase transformations occurring in these types of steels are investigated for the first time in-situ, aiding a detailed analysis of the austenite decomposition kinetics. For the low hardenability steel with main composition Fe-0.08C-1.7Mn-0.403Si-0.303Cr in weight percent, austenite decomposition to polygonal ferrite and bainite occurs already during the initial cooling. However, for the high hardenability steel with main composition Fe-0.08C-1.79Mn-0.182Si-0.757Cr-0.094Mo in weight percent, the austenite decomposition kinetics is retarded, chiefly by the Mo addition, and therefore mainly bainitic transformation occurs during isothermal holding; the bainitic transformation rate at the isothermal holding is clearly enhanced by lowered temperature from 550 °C to 500 °C and 450 °C. During prolonged isothermal holding, carbide formation leads to decreased austenite carbon content and promotes continued bainitic ferrite formation. Moreover, at prolonged isothermal holding at higher temperatures some degenerate pearlite form.

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