scholarly journals Growth Kinetics and Some Mechanical Properties of Plasma Paste Borided Layers Produced on Nimonic 80A-Alloy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5146
Author(s):  
Natalia Makuch ◽  
Piotr Dziarski ◽  
Michał Kulka ◽  
Mourad Keddam

Plasma paste boriding was employed in order to produce the boride layers on Nimonic 80A-alloy. The process was carried out at temperatures of 1023 K, 1073 K and 1123 K for 3, 4 and 6 h in a gas mixture of 50% H2-50% Ar. Borax paste was used as a boron source. The microstructure of the produced surface layers consisted of the mixture of nickel borides and chromium borides. The effect of processing temperature and duration on the thickness of the borided layers was observed. The theoretical thicknesses of the borided layers were estimated using an integral diffusion model. A good correlation was obtained between the theoretical (modeled) and experimental depths of the plasma paste borided layers. The boride layers were characterized by a high hardness ranging from 1160 HV to 2132 HV. The multiphase character of the produced layers resulted in differences in hardness. A significant improvement of the wear resistance of the plasma paste borided Nimonic 80A-alloy was observed in comparison with the non-borided alloy.

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.


2018 ◽  
Vol 12 (4) ◽  
pp. 4180-4190
Author(s):  
Ananda Hegde ◽  
Sathyashankara Sharma ◽  
Gowri Shankar M. C

When the ductile iron which is also known as Spheroidal Graphite (SG) iron, is subjected to austempering heat treatment, the material is known as austempered ductile iron (ADI). This material has good mechanical properties and has various applications in different fields. This revolutionary material with its excellent combination of strength, ductility, toughness and wear resistance has the potential to replace some of the commonly used conventional materials such as steel, aluminium and other light weight alloys as it offers production advantage as well. One of the problems encountered during manufacturing is machining of ADI parts owing to its high hardness and wear resistance. Many researchers over a period of time have reported the machinability aspects of the ADI. This paper presents a review on the developments made on the machinability aspects of ADI along with other mechanical properties.


2021 ◽  
pp. 557-564
Author(s):  
N.S. Ulakhanov ◽  
U.L. Mishigdorzhiyn ◽  
A.G. Tikhonov ◽  
A.I. Shustov ◽  
A.S. Pyatykh

The effect of diffusion high-temperature boroaluminizing (HBA) on the mechanical properties and quality parameters of the surface layer of stamp steels 5KhNM and 3Kh2V8F is shown. An analysis of the microstructure and composition of diffusion composite layers obtained as a result of thermal-chemical treatment (TCT) is presented and the distribution of microhardness in these layers is studied depending on the formed borides and carbides. The influence of processing temperature modes of on the parameters of roughness was experimentally established and the wear resistance characteristics of the processed surfaces of the investigated materials were determined.


2018 ◽  
Vol 8 (12) ◽  
pp. 2439 ◽  
Author(s):  
Yong Gao ◽  
Mingzhuo Zhou

Additive manufacturing (AM) nickel-based superalloys have been demonstrated to equate or exceed mechanical properties of cast and wrought counterparts but their tribological potentials have not been fully realized. This study investigates fretting wear behaviors of Inconel 625 against the 42 CrMo4 stainless steel under flat-on-flat contacts. Inconel 625 is prepared by additive manufacturing (AM) using the electron beam selective melting. Results show that it has a high hardness (335 HV), superior tensile strength (952 MPa) and yield strength (793 MPa). Tribological tests indicate that the AM-Inconel 625 can suppress wear of the surface within a depth of only ~2.4 μm at a contact load of 106 N after 2 × 104 cycles. The excellent wear resistance is attributed to the improved strength and the formation of continuous tribo-layers containing a mixture of Fe2O3, Fe3O4, Cr2O3 and Mn2O3.


2016 ◽  
Vol 872 ◽  
pp. 55-61 ◽  
Author(s):  
Kittipong Kimapong ◽  
Pramote Poonayom ◽  
Voraya Wattanajitsiri

Hard-facing welding is one of the repairing methods for increasing hard metal on the agricultural machine part surfaces that caused by the wear mechanism. To this date, the investigation of an optimized welding process parameter that could produce high hardness and wear resistance of the hard-facing layer is still being developed and performed. This paper aims to study the effects of hard-facing welding layer on mechanical properties and microstructure of hard-facing weld metal on JIS-50C carbon steel. The summarized results are as follows: (a) an increase of hard-facing layer affected to increase the hardness of the layer, (b) the hardness of the welds showed a maximum hardness of about 750 HV at a top surface of 3rd welds layers with no-buffering layer and showed the minimum hardness of about 225 HV at a base metal, (c) microstructure investigation showed that the increase of the phase that contained higher chromium, molybdenum and manganese affected the increase of the hardness and the wear resistance of the weld metal, (d) The minimum mass loss of 0.2559 mg/m could be found when a welding current of 100A, non-buffering layer and 3 layers of hard-facing weld metal were applied, and (e) the buffering layer was able to produce a sound weld metal and might not be suited for the hard-facing welding of the medium carbon steel because it produced the dilution effect that deteriorated the mechanical properties of the weld metal.


2011 ◽  
Vol 326 ◽  
pp. 144-150
Author(s):  
A. Mateen ◽  
Fazal Ahmad Khalid ◽  
T.I. Khan ◽  
G.C. Saha

Tungsten carbide cobalt coating has been extensively used for cutting and mining tools, aerospace, automotive and other wear resistance applications. These coatings not only have superior mechanical properties like high hardness, toughness and compressive strength but have also excellent controllable tribological properties. In this paper a comparison of wear properties and structural phases has been presented to consider for tribological applications. It is found that nanocrystalline duplex coatings have shown much superior properties as compared to the microcrystalline coatings. Evidence of clusters of WC particles was found in microcrystalline coating as compared to homogeneous dense coating structure observed in the nanocrystalline coating. These results are discussed to assess their suitability for super hard wear resistance applications.


2012 ◽  
Vol 727-728 ◽  
pp. 1085-1091
Author(s):  
José Vitor C. Souza ◽  
O.M.M. Silva ◽  
E.A. Raymundo ◽  
João Paulo Barros Machado

Si3N4based ceramics are widely researched because of their low density, high hardness, toughness and wear resistance. Post-sintering heat treatments can enhance their properties. Thus, the objective of the present paper was the development of a Si3N4based ceramic, suitable for structural applications, by sintering in nitrogen gas pressure, using AlN, Al2O3, and Y2O3as additives and post-sintering heat treatment. The green bodies were fabricated by uniaxial pressing at 80 MPa with subsequent isostatic pressing at 300 MPa. The samples were sintered at 1900°C for 1 h under N2gas pressure of 0.1 MPa. Post-sintering heat treatment was performed at 1500°C for 48 h under N2gas pressure of 1.0 MPa. From the results, it was observed that after post-sintering heat treatment there was a reduction of α-SiAlON phase and increase of β-Si3N4phase, with consequent changing in grain size, decrease of fracture toughness and increase of the Vickers hardness.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 719
Author(s):  
Yuki Hirata ◽  
Ryotaro Takeuchi ◽  
Hiroyuki Taniguchi ◽  
Masao Kawagoe ◽  
Yoshinao Iwamoto ◽  
...  

Amorphous boron carbon nitride (a-BCN) films exhibit excellent properties such as high hardness and high wear resistance. However, the correlation between the film structure and its mechanical properties is not fully understood. In this study, a-BCN films were prepared by an arc-sputtering hybrid process under various coating conditions, and the correlations between the film’s structure and mechanical properties were clarified. Glow discharge optical emission spectroscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy were used to analyze the structural properties and chemical composition. Nanoindentation and ball-on-disc tests were performed to evaluate the hardness and to estimate the friction coefficient and wear volume, respectively. The results indicated that the mechanical properties strongly depend on the carbon content in the film; it decreases significantly when the carbon content is <90%. On the other hand, by controlling the contents of boron and nitrogen to a very small amount (up to 2.5 at.%), it is possible to synthesize a film that has nearly the same hardness and friction coefficient as those of an amorphous carbon (a-C) film and better wear resistance than the a-C film.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mahboobeh Azadi ◽  
Alireza Sabour Rouhaghdam ◽  
Shahrokh Ahangarani

In the PACVD technique, temperature and gas flow rate are two important parameters affecting the coating characteristics. Effect of these parameters on mechanical behaviors of TiC coating that was deposited on hot work tool steel (H13) was investigated in this paper. We analyzed TiC coating composition and structure with grazing incidence X-ray diffraction (GIXRD) and Fourier transformation infrared spectroscopy (FTIR). The mechanical properties of the coatings, such as microhardness, wear resistance, and surface roughness, were studied with Knoop hardness indentation, pin on disk wear tests, and atomic force microscopy, respectively. When the deposition temperature decreased from 490°C to 450°C and the CH4 to TiCl4 flow rate ratio was also increased from 1.5 to 6, TiC coating color changed from dark gray to silver. The best mechanical properties such as a high hardness (27 GPa), wear resistance, and low surface roughness were related to the coating that was deposited at 450°C.


2021 ◽  
Vol 324 ◽  
pp. 15-20
Author(s):  
Tong Chen ◽  
Shinji Koyama

Surface oxidation of pure titanium was performed in the atmosphere to increase the mechanical properties. The effect of oxidation temperature (650-900°C) for 2 h on the microstructure, composition, and mechanical properties of the treated samples was investigated using X-ray diffraction, hardness tester and indentation modulus tester, respectively. The diffusion rate of oxygen in grade-2 pure Ti with different processing temperatures discussed in present research. Based on a result of the examination, the surface hardness was increased first and then decreased as the processing temperature increased. And when the processing temperature at 850°C, the surface hardness reached the maximum value. In addition, the Young's modulus of the treated samples also showed a maximum value of 198.9 GPa for a processing temperature of 850°C. An oxidation condition of 850°C is considered optimal as it provides sufficiently high hardness during practical use.


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