Detonation Spraying of Metal Carbides Composites

2021 ◽  
Vol 1016 ◽  
pp. 88-93
Author(s):  
Vladimir Ulianitsky ◽  
Alexandr Shtertser ◽  
Igor Batraev ◽  
Maria Doubenskaia ◽  
Igor Smurov

Detonation spraying is used for the binary fuel spraying, C2H2/C3H8/O2 of WC/Co and Cr3C2/NiCr powder. The particles-in-flight temperature and velocity are calculated and optimized. Spraying distance is varied from 50 to 400 mm and substrate inclination relatively spraying direction is varied up to 60o. Coating properties: microstructure, microhardness, porosity, wear resistance are measured and it is found that binary fuel detonation spraying provides high coating quality. For example, for the WC/Co (88/12 wt%) coatings: porosity is less than 0.7%; microhardness is about 1500 HV300; ASTM G65 abrasion wear is 1.17 mm3/1000 rev when using a corundum powder as an abradant. For the Cr3C2/NiCr (75/25 wt%) coatings porosity is less than 1.7%, microhardness is about 800 HV300, and abrasion wear is 2.7 mm3/1000 rev. It is found that the coating performance does not decrease strongly with the substrate inclination up to 30o. The industrial applications include machinery, aircraft, petrol, gas turbines domains, etc.

Author(s):  
Maximilian Grimm ◽  
Susan Conze ◽  
Lutz-Michael Berger ◽  
Rico Drehmann ◽  
Thomas Lampke

AbstractCoatings prepared from chromia-rich (Al,Cr)2O3 solid solution (ss) feedstock powders are intended to improve the properties of Cr2O3 coatings, but are rarely studied so far. In this work, the processability of a commercial (Al,Cr)2O3 solid solution (ss) powder containing 78 wt.% Cr2O3 by atmospheric plasma spraying (APS), the corresponding coating microstructures and properties were investigated. Possible further improvements were expected by blending with 2, 23 and 54 wt.% TiOx powder. For comparison, plain Cr2O3 and TiOx coatings were studied as well. The microstructures were analyzed using SEM, EDS and XRD measurements. Hardness (HV0.3) was measured, as well as the dry unidirectional sliding wear resistance and the abrasion wear resistance (ASTM G65). Moreover, the corrosion and electrical insulating properties were measured. The (Al,Cr)2O3 ss showed only a small change of the composition, and the formation of γ-Al2O3, as found for alumina-rich (Al,Cr)2O3 ss powders, was avoided. Compared to the plain chromia coating, some improvements of the processability and coating properties for the ss (Al,Cr)2O3 coating were found. The most balanced coating performance was achieved by blending the ss (Al,Cr)2O3 with 2 wt.% TiOx, as this coating showed both a high sliding and abrasion wear resistance, in combination with a high corrosion resistance.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1774
Author(s):  
Elżbieta Cygan-Bączek ◽  
Piotr Wyżga ◽  
Sławomir Cygan ◽  
Piotr Bała ◽  
Andrzej Romański

The work presents the possibility of fabricating materials for use as a matrix in sintered metallic-diamond tools with increased mechanical properties and abrasion wear resistance. In this study, the effect of micro-sized SiC, Al2O3, and ZrO2 additives on the wear behaviour of dispersion-strengthened metal-matrix composites was investigated. The development of metal-matrix composites (based on Fe–Mn–Cu–Sn–C) reinforced with micro-sized particles is a new approach to the substitution of critical raw materials commonly used for the matrix in sintered diamond-impregnated tools used for the machining of abrasive stone and concrete. The composites were prepared using spark plasma sintering (SPS). Apparent density, microstructural features, phase composition, Young’s modulus, hardness, and abrasion wear resistance were determined. An increase in the hardness and wear resistance of the dispersion-strengthened composites as compared to the base material (Fe–Mn–Cu–Sn–C) and the commercial alloy Co-20% WC provides metallic-diamond tools with high-performance properties.


2011 ◽  
Vol 690 ◽  
pp. 405-408 ◽  
Author(s):  
Joel Voyer

Partially amorphous iron-based coatings were produced onto aluminium using a powder flame-spraying process with a commercially available feedstock powder (Nanosteel SHS-7170) obtained from the Nanosteel Company Inc.. Several coating properties such as the microstructure, porosity, phase content, micro-hardness, and wear resistance were evaluated in the as-sprayed condition. As shown by the results obtained, the powder flame iron-based coatings perform relatively well in term of wear resistance in comparison with similar coatings produced using other expensive thermal spray techniques. Furthermore, this study shows that all the coating properties (microstructure, porosity, phase content, hardness and wear performance) depend strongly on the flame spraying parameters used. Finally, this paper demonstrates clearly that the flame-spray process may be used to produce amorphous iron-based coatings having a good wear resistance, and that this process appears to be a suitable inexpensive alternative to plasma or HVOF processes based on the present results.


Author(s):  
John Hartranft ◽  
Bruce Thompson ◽  
Dan Groghan

Following the successful development of aircraft jet engines during World War II (WWII), the United States Navy began exploring the advantages of gas turbine engines for ship and boat propulsion. Early development soon focused on aircraft derivative (aero derivative) gas turbines for use in the United States Navy (USN) Fleet rather than engines developed specifically for marine and industrial applications due to poor results from a few of the early marine and industrial developments. Some of the new commercial jet engine powered aircraft that had emerged at the time were the Boeing 707 and the Douglas DC-8. It was from these early aircraft engine successes (both commercial and military) that engine cores such as the JT4-FT4 and others became available for USN ship and boat programs. The task of adapting the jet engine to the marine environment turned out to be a substantial task because USN ships were operated in a completely different environment than that of aircraft which caused different forms of turbine corrosion than that seen in aircraft jet engines. Furthermore, shipboard engines were expected to perform tens of thousands of hours before overhaul compared with a few thousand hours mean time between overhaul usually experienced in aircraft applications. To address the concerns of shipboard applications, standards were created for marine gas turbine shipboard qualification and installation. One of those standards was the development of a USN Standard Day for gas turbines. This paper addresses the topic of a Navy Standard Day as it relates to the introduction of marine gas turbines into the United States Navy Fleet and why it differs from other rating approaches. Lastly, this paper will address examples of issues encountered with early requirements and whether current requirements for the Navy Standard Day should be changed. Concerning other rating approaches, the paper will also address the issue of using an International Organization for Standardization, that is, an International Standard Day. It is important to address an ISO STD DAY because many original equipment manufacturers and commercial operators prefer to rate their aero derivative gas turbines based on an ISO STD DAY with no losses. The argument is that the ISO approach fully utilizes the power capability of the engine. This paper will discuss the advantages and disadvantages of the ISO STD DAY approach and how the USN STD DAY approach has benefitted the USN. For the future, with the advance of engine controllers and electronics, utilizing some of the features of an ISO STD DAY approach may be possible while maintaining the advantages of the USN STD DAY.


2013 ◽  
Vol 341-342 ◽  
pp. 92-95
Author(s):  
Li Jun Wang ◽  
Jian Jun Hao ◽  
Yue Jin Ma ◽  
Jian Guo Zhao ◽  
Jian Chang Li

Using plasma spraying equipment to prepare Al2O3-13wt%TiO2 coating on Q235 substrate. Study of its organization and performance, test the performance of coating microhardness and the resistance of friction and wear resistance then optimize the spraying process parameters. The surface of the coating performance was studied by SEM. The results show that, Coating microhardness can be as high as 1132HV, Far more than the matrix microhardness. The minimum average wear weightlessness of Sample surface is 0.95mg. Greatly improve the wear resistance


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