Formation of boride layers on a commercially pure Ti surface produced via powder metallurgy

Author(s):  
Yavuz Kaplan ◽  
Mehmet Gülsün ◽  
Sinan Aksöz

Abstract In this study, powder metallurgy was applied in a furnace atmosphere to form titanium boride layers on a commercially pure Ti surface. Experiments were carried out using the solid-state boriding method at 900 °C and 1000°C for 12 h and 24 h. Samples were produced by pressing the commercially pure Ti powders under 870 MPa. The sintering process required by the powder metallurgy method was carried out simultaneously with the boriding process. Thus, the sintering and boriding were performed in one stage. The formation of the boride layer was investigated by field emission scanning electron microscopy, optical-light microscopy, X-ray diffraction, and elemental dispersion spectrometry analyses. In addition, microhardness measurements were performed to examine the effect of the boriding process on hardness. The Vickers microhardness of the boronized surface reached 1773 HV, which was much higher than the 150 HV hardness of the commercially pure Ti substrate. The X-ray diffraction analysis showed that the boriding process had enabled the formation of TiB and TiB2 on the powder metallurgy Ti substrate surface. Consequently, the production of Ti via powder metallurgy is a potentially cost-effective alternative to the conventional method, and the boriding process supplies TiB and TiB2 that provide super-high hardness and excellent wear and corrosion resistance.

Author(s):  
S. Rajeshkannan ◽  
I. Manikandan ◽  
M. Vigneshkumar

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.


2015 ◽  
Vol 365 ◽  
pp. 122-127 ◽  
Author(s):  
N. López-Perrusquia ◽  
M.A. Doñu Ruiz ◽  
C. R. Torres San-Miguel ◽  
M. Flores-Báez ◽  
I. Flores-Báez

In this study, we present a boronizing treatment on a steel microalloy that was performed according to dehydrated paste-pack boriding. The temperatures conducted were at 1173, 1223 and 1273 K; at various exposure times of 1, 3, 6 and 9 h. As a result of the boriding process, diffusion-controlled growth of the FeB/Fe2B layers was obtained at the surface of the micro-alloy steel, and the kinetics of the growth process changed parabolically over time. The results of these examination properties of the boride layer as revealed by Optical Microscopy (OP) showed the morphology of the boride layer as a saw-tooth with a thickness ranging from 33 μm to 220 μm depending on the boronizing time. The analysis of Scanning Electron Microscopy (SEM-EDS); showed a distribution of the alloying elements that were detected by Energy Dispersive Spectrometry. The X-ray diffraction (XRD) technique indicated that the surface was a mixture of FeB and Fe2B borides. The evaluation of adhesion of the layers was determined by the technique of Rockwell-C hardness. Young’s modulus and hardness of the layer were evaluated by a nanoindentation technique with a load of 250 mN. The paste dehydrate boriding of micro-alloy reveal a change of properties on the surface; also the coatings FeB and Fe2B, to make a sacrificial function in the steels micro alloyed as widely used in pipelines transporting oil.


2008 ◽  
Vol 368-372 ◽  
pp. 852-854 ◽  
Author(s):  
Gang Shao ◽  
Hai Long Wang ◽  
Fang Shao ◽  
Kai Li ◽  
Rui Zhang

SiC particulate-reinforced Fe composites were prepared by a powder metallurgy (PM) and conventional atmospheric sintering method. X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques were used to characterize the obtained composites. The coating layer of Cu on SiC particles can suppress the reaction between SiC and Fe until 1250oC. The maximum microhardness of 283 Hv appears at near 1250oC. Substantial reaction occurs at above 1250oC, which leads to the deterioration in the microstructure and related properties. The inter-metallic compounds of FeSi or Fe2Si were detected which contributed to the enhancement of the interface between SiC and Fe.


2016 ◽  
Vol 71 (11) ◽  
pp. 1017-1020
Author(s):  
Nazim Ucar ◽  
Sule Dogan ◽  
Mustafa Serdar Karakas ◽  
Adnan Calik

AbstractBoriding of binary Ni–Ti shape memory alloys was carried out in a solid medium at 1273 K for 2, 4, 6, and 8 h using the powder pack method with proprietary Ekabor–Ni powders. Characterization of the boride layer formed on the surface of alloys was done by optical microscopy and scanning electron microscopy. The presence of boride, silicide, and borosilicide phases in the boride layers was confirmed by X-ray diffraction analysis. The thickness and microhardness of the boride layers increased with increasing boriding time. Hardness profiles showed a rapid decrease in hardness moving from the boride layer to the main structure. The high hardness of the boride layer was attributed mainly to the formation of TiB2. A parabolic relationship was observed between layer thickness and boriding time, and the growth rate constant for the boriding treatment was calculated as 0.62×10−8 cm2 s−1.


The Tungsten carbide (WC) based composites are good choice to replace the traditional conventional materials for obtaining high hardness and wear resistance. This work investigates the influence of cobalt content on the characterization of Tungsten carbide. The composite specimens are prepared by using powder metallurgy technique. The effect of cobalt material on the performance of Tungsten carbide hardness, fracture toughness is estimated by conducting suitable experiments. While performing experiments, a powder mixture of 89% WC, 11% of Co was manufactured with powder metallurgy, under appropriate milling conditions and Sintering temperature to ensure uniform microstructure. From the present work the optimum sintering temperature of Tungsten carbide mixed nano cobalt composite is identified. The crystalanity of the resulting materials is identified from a rapid analytical technique, X -ray Diffraction.


2021 ◽  
Vol 2 (1) ◽  
pp. 001-010
Author(s):  
Amir Arifin ◽  
Gunawan Gunawan ◽  
Alim Mardhi ◽  
Agung Nurmansyah Putra Wijaya ◽  
Endra Sujatmika

Metal matrix composite has been used widely in some applications such as the automotive and aerospace industries. In this work, Aluminum/Fly ash composite material was made with an egg yolk space holder and the manufacturing process was successfully carried out. The process includes the mixing, stirring, drying, and sintering processes that were undertaken including the powder metallurgy method. The metal form has successfully been fabricated however the hardness test results for specimens were not very satisfactory. The Aluminum/Fly ash porous composite materials with egg yolk space holders were was characterized using X-Ray Florence (XRF), X-Ray Diffraction (XRD) test by producing the main peak of Al N and Al2O3. Observation of SEM by showing phenomena such as; cracks, alignment, and porous. Density Testing by producing an average porosity of 28.87%. The observation of Optical Microscopes by showing the shape of the shaft that is not homogeneous.


Author(s):  
J. Alias

Much research on magnesium (Mg) emphasises creating good corrosion resistance of magnesium, due to its high reactivity in most environments. In this study, powder metallurgy (PM) technique is used to produce Mg samples with a variation of aluminium (Al) composition. The effect of aluminium composition on the microstructure development, including the phase analysis was characterised by optical microscope (OM), scanning electron microscopy (SEM) and x-ray diffraction (XRD). The mechanical property of Mg sample was performed through Vickers microhardness. The results showed that the addition of aluminium in the synthesised Mg sample formed distribution of Al-rich phases of Mg17Al12, with 50 wt.% of aluminium content in the Mg sample exhibited larger fraction and distribution of Al-rich phases as compared to the 20 wt.% and 10 wt.% of aluminium content. The microhardness values were also increased at 20 wt.% and 50 wt.% of aluminium content, comparable to the standard microhardness value of the annealed Mg. A similar trend in corrosion resistance of the Mg immersed in 3.5 wt.% NaCl solution was observed. The corrosion behaviour was evaluated based on potentiodynamic polarisation behaviour. The corrosion current density, icorr, is observed to decrease with the increase of Al composition in the Mg sample, corresponding to the increase in corrosion resistance due to the formation of aluminium oxide layer on the Al-rich surface that acted as the corrosion barrier. Overall, the inclusion of aluminium in this study demonstrates the promising development of high corrosion resistant Mg alloys.


Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Daria V. Mamonova ◽  
Anna A. Vasileva ◽  
Yuri V. Petrov ◽  
Denis V. Danilov ◽  
Ilya E. Kolesnikov ◽  
...  

Surfaces functionalized with metal nanoparticles (NPs) are of great interest due to their wide potential applications in sensing, biomedicine, nanophotonics, etc. However, the precisely controllable decoration with plasmonic nanoparticles requires sophisticated techniques that are often multistep and complex. Here, we present a laser-induced deposition (LID) approach allowing for single-step surface decoration with NPs of controllable composition, morphology, and spatial distribution. The formation of Ag, Pt, and mixed Ag-Pt nanoparticles on a substrate surface was successfully demonstrated as a result of the LID process from commercially available precursors. The deposited nanoparticles were characterized with SEM, TEM, EDX, X-ray diffraction, and UV-VIS absorption spectroscopy, which confirmed the formation of crystalline nanoparticles of Pt (3–5 nm) and Ag (ca. 100 nm) with plasmonic properties. The advantageous features of the LID process allow us to demonstrate the spatially selective deposition of plasmonic NPs in a laser interference pattern, and thereby, the formation of periodic arrays of Ag NPs forming diffraction grating


2021 ◽  
Author(s):  
Mei Yang ◽  
Yishu Zhang ◽  
Haoxing You ◽  
Richard Smith ◽  
Richard D. Sisson

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.


2006 ◽  
Vol 59 (2) ◽  
pp. 225-232 ◽  
Author(s):  
Pierre Yves Jouan ◽  
Arnaud Tricoteaux ◽  
Nicolas Horny

The aim of this paper is first a better understanding of DC reactive magnetron sputtering and its implications, such as the hysteresis effect and the process instability. In a second part, this article is devoted to an example of specific application: Aluminium Nitride. AlN thin films have been deposited by reactive triode sputtering. We have studied the effect of the nitrogen contents in the discharge and the RF bias voltage on the growth of AlN films on Si(100) deposited by triode sputtering. Stoichiometry and crystal orientation of AlN films have been characterized by means of Fourier-transform infrared spectroscopy, X-ray diffraction and secondary electron microscopy. Dense and transparent AlN layers were obtained at high deposition rates. These films have a (002) orientation whatever the nitrogen content in the discharge, but the best crystallised ones are obtained at low value (10%). A linear relationship was observed between the AlN lattice parameter "c" (perpendicular to the substrate surface) and the in-plane compressive stress. Applying an RF bias to the substrate leads to a (100) texture, and films become amorphous. Moreover, the film's compressive stress increases up to a value of 8GPa before decreasing slowly as the bias voltage increases.


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