Surface Hardness Modify and Improve Wear Properties of EP\ NanoZrO2

2021 ◽  
Vol 19 (2) ◽  
pp. 77-82
Author(s):  
Fadhil K. Farhan ◽  
Aws Abbas Hussein ◽  
Ali Q. Tuama

The liquid and mechanical mixing method was used in addition to ultrasound technology to prepare samples according to standard conditions. The percentage of cementing with ceramic powder was adopted from 1% to 4% as a weight ratio, and by using mixing drivers, nanocomposites were prepared depending on the theoretical density of the components. The velvet density was measured using Archimedes' method, and the results showed a successive improvement and increase in density with the weight ratio of addition. The results of the particulate hardness test showed a significant improvement in the results of the prepared nanostructures compared to the base sample (pure epoxy). With regard to the properties of wear resistance (wear modulus) using the screw-on-disk method, the cemented samples showed a higher wear resistance compared to the base sample. The results were interpreted based on the values of density and hardness in addition to the properties possessed by the ceramic powder of high surface area and average granular size of 32 nanometers through scanning electron microscopy. In this work, nanostructures based on (a polymer) supported with nanoscale zirconium dioxide powder were developed.

2014 ◽  
Vol 966-967 ◽  
pp. 386-396 ◽  
Author(s):  
Yuan Ching Lin ◽  
Jia Bin Bai ◽  
Jiun Nan Chen

The austenitic stainless steel (SS) of AISI 304L is widely used in industrial applications because of its superior anti-corrosion resistance. However, the material suffers from a lower hardness, thus reducing wear resistance. In this study, AISI 304L was clad with tungsten boride (WB) ceramic powder using the gas tungsten arc welding (GTAW) process to increase surface hardness and improve wear resistance. The microstructure of the cladding layer was investigated using an X-ray diffractometer (XRD), an electron probe microanalyzer (EPMA), and a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS). The hardness distribution of the cladding layer was measured using a micro-Vickers hardness tester. Wear tests were conducted with a pin-on-disc tribometer at the ambient condition, while simultaneously monitoring friction coefficient variation. Surface frictional temperature was recorded with K-type thermocouples during wear tests. The worn morphology of the tested specimens was observed by SEM to identify wear characteristics. The results show that WB cladding successfully increased the hardness and the wear resistance of AISI 304L. Keywords: GTAW, WB, wear resistance, microstructure


1998 ◽  
Vol 26 ◽  
pp. 69-72 ◽  
Author(s):  
Martin Schneebeli ◽  
Cécile Coléou ◽  
François Touvier ◽  
Bernard Lesaffre

Time-domain reflectometry (TDR) is widely used in soil physics to determine water content. Existing equipment and methods ran be adapted to measurements of snow wetness. The main advantages compared to other methods are flexibility in constructing sensors, minimal influence on snow cover during measurements and sensors can be multiplexed. We developed sensors suitable for continuous and non-continuous measurements of snow wetness and density, measured the apparent permittivity in different snow densities and snow types, and compared the measurements to existing mixing formulas for mixtures of snow and air. In dry snow, density was measured from 110 to 470 kg m−3. The residual error is 14 kg m −3 and the 95% confidence interval of our model is 3 kg m−3. To measure snow density and wetness continuously suitable sensors have been constructed. Their small size and high surface area to weight ratio minimizes their movement in the snowpack, except when they are exposed to intense solar radiation. Results show that changes in dry-snow density of less than 5 kgm−3 can be detected. Infiltration of even small amounts of water clearly shows up in the permittivity. At the surface of the snowpack, problems occur due to the formation of air pockets around the sensors during long-term measurements.


2018 ◽  
Vol 44 ◽  
pp. 00165 ◽  
Author(s):  
Karolina Sobczyk ◽  
Karol Leluk

Poly(lactic acid) electrospinning tests were carried out under various process conditions. Openwork structures with a high surface area to weight ratio have been obtained. Changing the parameters of the PLA electrospinning process resulted in products with different fiber morphology.


1998 ◽  
Vol 26 ◽  
pp. 69-72 ◽  
Author(s):  
Martin Schneebeli ◽  
Cécile Coléou ◽  
François Touvier ◽  
Bernard Lesaffre

Time-domain reflectometry (TDR) is widely used in soil physics to determine water content. Existing equipment and methods ran be adapted to measurements of snow wetness. The main advantages compared to other methods are flexibility in constructing sensors, minimal influence on snow cover during measurements and sensors can be multiplexed. We developed sensors suitable for continuous and non-continuous measurements of snow wetness and density, measured the apparent permittivity in different snow densities and snow types, and compared the measurements to existing mixing formulas for mixtures of snow and air. In dry snow, density was measured from 110 to 470 kg m−3. The residual error is 14 kg m −3 and the 95% confidence interval of our model is 3 kg m−3. To measure snow density and wetness continuously suitable sensors have been constructed. Their small size and high surface area to weight ratio minimizes their movement in the snowpack, except when they are exposed to intense solar radiation. Results show that changes in dry-snow density of less than 5 kgm−3 can be detected. Infiltration of even small amounts of water clearly shows up in the permittivity. At the surface of the snowpack, problems occur due to the formation of air pockets around the sensors during long-term measurements.


2016 ◽  
Vol 10 (2) ◽  
pp. 157
Author(s):  
Fitria Rahmawati ◽  
Indah Rizki Fitriani ◽  
Abu Masykur

<p>A Research on CdS synthesis in reverse microemulsion of Igepal CO-720 system has been conducted at various weight ratio of water to surfactant. Igepal CO-720 naturally forms  oil  in  water  (o/w)  emulsion  type  due  to  its  high  HLB  (Hydrophilic -Lipophilic Balance)  value.  Therefore,  in  this  research  the  Igepal  CO-720  system  was  inversed  into water  in  oil  (w/o)  system  before  it  was  used  as  microreactor  for  CdS  synthesis.  As comparison,  a  system  of  AOT  (Aerosol  OT;  sodium  bis (2-ethylhexyl)  sulfosuccinate) which  is  naturally  w/o  system  was  also  used  as  microreactor  for  CdS  synthesis.  The prepared  CdS  was  analyzed  by  X-ray  diffraction  for  crystal  identification,  scanning electron microscope for morphological analysis, UV-Vis for absorption edge determination and  photoelectrochemical  testing  for  photoactivity.  The  results  show that the  Igepal  CO -720  system can  be  inverted  into  w/o  system  and  can  be  used  as  microreactor  for  CdS synthesis. The prepared CdS is in nanosize with the average diameter of 2.517  ±  0.014 nm and  the  average  gap  energy  of  3.805  ±  0.178  eV.  The  prepared  CdS  in  Igepal  CO-720 system has less regular form in comparison with morphology of the prepared CdS in AOT system. As the ω  values decreases the particle diameter decreases, the gap energy increases and the %  IPCE increases. It indicates that high surfactant concentration allows small size micelles  formation  and  produced  smaller  CdS  particle  that  has  high  surface  area  and therefore  provide  higher  photocatalytic  activity  which  was  indicated  by  high  value  of  its % IPCE.</p>


Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 996
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff ◽  
Laura L. Greiner

Pre-weaning morality (PWM) is attributed to a poor creep area microclimate and causes major economic and productivity losses for the US swine industry. Piglets need supplementary heat to overcome a high surface area to body weight ratio and minimal thermoregulation. A pilot-scale study was conducted to evaluate a semi-enclosed heated microclimate (SEHM) as a supplementary heat source for farrowing creep areas over six farrowing cycles (from January to July 2019) in two rooms with 24 farrowing stalls in each room. Six SEHMs (each SEHM covers two stalls) were randomly distributed to each room and compared to heat lamps (HLs) for productivity and electricity usage. Data from 113 (SEHM) and 101 litters (HL) showed no significant difference between treatments in average daily gain (p = 0.26), 252.4 ± 8.0 g hd−1 d−1 (SEHM) and 260.3 ± 8.1 g hd−1 d−1 (HL) and PWM (p = 0.08), 9.67% ± 0.82% (SEHM) and 12.04% ± 0.87% (HL). However, a significant difference (p = 0.02) was noted in the PWM attributed to over-lay mortalities, 4.05% ± 0.76% (SEHM) compared to 6.04% ± 0.78% (HL). The SEHM electricity averaged 3.25 kWh d−1 (2.91, 3.59 kWh d−1; 95% CI), which was significantly different (p < 0.01) from the HL equivalent (125 W bulb; 6 kWh d−1).


Alloy Digest ◽  
1977 ◽  
Vol 26 (3) ◽  

Abstract UHB RIGOR AR is a chromium-molybdenum-vanadium tool steel characterized by high surface hardness, high hardenability, high dimensional stability after hardening and tempering, high compression resistance, good machinability, good resistance to tempering and good wear resistance. Its many uses include metal-working tools, dies for porcelain and gages. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-315. Producer or source: Uddeholm Aktiebolag.


2018 ◽  
Vol 781 ◽  
pp. 101-107
Author(s):  
Yurii Ivanov ◽  
Olga V. Krysina ◽  
Pavel Moskvin ◽  
Elizaveta A. Petrikova ◽  
Olga V. Ivanova ◽  
...  

Commercially pure A7 aluminum was exposed to surface modification in a single vacuum cycle which included vacuum arc evaporation and deposition of commercially pure titanium and intense electron beam irradiation and melting of the film–substrate system using a plasma-cathode pulsed electron source. The deposited Ti film thickness was 0.5 and 1 μm. The irradiated Ti–Al system revealed a multilayer multiphase structure consisting of submicro-and nanosized elements with intermetallic inclusions Al3Ti, Al2Ti, and TiAl3. The Ti film during irradiation broke up into fragments with their immersion in the molten Al surface layer to a depth of 20 μm. The modified material surpassed the initial aluminum in wear resistance by a factor of 2.4 and in microhardness by a factor larger than 4. The main cause for the high surface hardness and high wear resistance of the modified aluminum was likely the formation of both the intermetallic particles and the Ti-hardened transition layer.


2011 ◽  
Vol 399-401 ◽  
pp. 1958-1961
Author(s):  
Lin Qin ◽  
Kun Kun Yang ◽  
Shuai Wang ◽  
Bin Tang

Cr-Mo surface alloying modified layers on Ti6Al4V alloy were prepared using double glow discharge plasma alloying technique. The surface hardness and the resistance ability of repeated impact of the layers were measured using Knoop hardness test and repeated impact test respectively. The results show that the surface hardness of the modified samples was significantly improved due to the deposited layer containing Cr1.93Ti1.07, Cr2Ti, FeCrMo, and Cr2Ti4O11 compounds. However, it was found that heavy peeling occurred on the Cr-Mo alloying modified layers after repeated impact test due to these brittle phases formed in plasma alloying process. Brittle phases appeared in the surface modified layer, such as intermetallic compounds, contribute to hardness enhancement and wear properties, but may be detrimental to impact resistance.


2021 ◽  
Vol 15 (58) ◽  
pp. 179-190
Author(s):  
Fedaoui Kamel ◽  
Amar Talhi ◽  
Mohamed Zine Touhami

This study, concerns the improvement of the hardness and resistance to wear of the Ti-6Al-4V alloy surface by means of thermochemical treatment, for obtaining coatings on the Ti-6Al-4V alloy gives performance of resistance to wear phenomena. Three-thermochemical treatment time (2h, 4h, and 6h) was chosen for investigation of the effect of such treatment on this alloy. The hardness test under an indentation load of 50 gf with a Vickers pyramidal indenter revealed that the surface hardness is 335 Hv for the untreated samples. On the other hand the hardness reaches approximately 1500 Hv during gas cementation at 930 °C for variable times (2h, 4h, 6h) followed by quenching at 840 °C in an oil medium, which was accompanied by a significant improvement in wear resistance. The characterization of the modified surface layers was made by means of a microscopic analysis and by X-ray diffraction. The case-hardening made it possible to obtain a wear resistance greater than that of the alloy not treated, minimal loss of mass by dry friction and an improvement in roughness as well as a good coefficient of friction.


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