Functional plasma-deposited coatings

The paper focuses on the problem of low adhesion of plasma sprayed coatings to the substrate. The subsequent laser treatment modes and their influence on the coatingsubstrate interface were studied. This allows to decrease the level of met-stability of the coating, thus decreasing its hardness down to 11–12 GPa on the surface and to about 9 GPa on depth of 400 µm. The redistribution of alloying elements through solid and liquid diffusion improves mechanical properties and rises the adhesion up to 450 MPa after remelting and up to 90–110 MPa after laser-aided thermal cycling. At the same time, remelting of coating helps to decrease its porosity down to 1%. The obtained complex of properties also allows to improve wear resistance of coatings and to decrease friction factor

Powder Eutectic Materials of Fe-Mn-C-B System for Coatings of Increased Abrasive Wear

In this chapter, selected problems of manufacturing coatings with high wear resistance obtained based on eutectic materials of the quaternary Fe-Mn-C-B system are discussed. With regard to the structural state and physico-mechanical properties of eutectic powder alloys and coatings correspond to the composite dispersion-strengthened materials. The formation of a hardened layer with the structure of eutectic on the metal surface is the creation of a new material with certain mechanical properties. The analysis of different material properties and of alloy addition enabled to work out new eutectic powder alloys based on iron of the Fe-Mn-C-B system. In particular, it enabled to determine eutectic ranges and element contents

Assessment of the Al–Fe–Ti system

The Al–Fe–Ti system has been assessed and the limiting binary systems are shortly reviewed. Based on a thorough review of the literature, isotherms at 800, 900, and 1000 °C have been re-evaluated and a provisional isotherm at 1200 °C is presented for the first time. The effect of alloying the binary phases with the third component is reviewed with regard to the ternary homogeneity ranges, crystallography, order/disorder transformations, and site occupancies. Of the variously reported ternary compounds only the existence of “Al2FeTi” (τ2) and “Al8FeTi3” (τ3) is confirmed. The occurrence of the phases τ2*, τ′2, and of a new stacking variant of TiAl is still under discussion, while the existence of the phases Fe2AlTi (τ1) and Fe25Al69Ti6 (X) is ruled out. The presented reaction scheme corroborates the isothermal sections and also a representation of the liquidus surface is given. Magnetic, electrical, thermochemical, atomistic and diffusion data for Al–Fe–Ti alloys are summarised and an overview about studies on modelling of phase equilibria and phase transformations is given

Phase Equilibrium and Microstructure Examinations of Eutectic Fe-C-Mn-B Alloys

In this study, we analyzed the quaternary Fe-C-Mn-B system to create new eutectic cast alloys for coating deposition and additive manufacturing. Experimental samples were fabricated via the wire arc manufacturing method with argon shielding using Kemppi Pro 5200 Evolution equipment. Annealing was performed in a vacuum electric furnace at 1273 K for 350 h. For phase analyses, Jeol Superprobe 733 equipment was used. Metallographic and differential thermal analyses were used to reveal the eutectic structure of the samples. Examinations of the quaternary Fe-C-Mn-B system demonstrated that several eutectic alloys existed in the system. Four isothermal pseudo-ternary sections of the Fe-C-Mn-B system were studied: “Fe3B”-Fe3C-“Fe3Mn”; Fe2B-“Fe2C”-“Fe2Mn”; “Fe3B”-Fe3C-“Fe1.2Mn”; “Fe23B6”-“Fe23C6”-“Fe23Mn”. Broad eutectic concentrations enabled us to overcome parameter fluctuations during additive manufacturing. In each isothermal section, two dissimilar phase regions were determined: one with a ternary Fe-C-B composition and the other with a ternary Fe-C-Mn composition. Depending on the manganese content, two types of solid solutions could be formed: (Fe, Mn)α or (Fe, Mn)γ

Development of eutectic powder alloys and coatings of iron - manganese - carbon - boron system for wear resistance of machinery parts

Phase equilibria in iron - manganese - carbon - boron system were determined to detect the eutectic regions and their concentration. A mathematic model of diffusion process under condition D(C) was developed. A mechanism of eutectic coating formation was determined. A scientific basis of alloys formation with given chemical composition, structure and properties was developed. The results obtained were applied in industry. New eutectic powder alloys increase a wear resistance of machinery parts, agriculture technique and tools 2-15 timesAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

BEAM–TO-COLUMN CONNECTION CALCULATIONS USING ROBOT SOFTWARE

A beam–to-column connection design and results of engineer calculations using Autodesk’s Robot Structural analysis are shown in the article. Two types of connections, bolted and welded, were calculated. The tensile resistance amounted to 912.74 kN, bending resistance to 100.87 kN·m and effective design capacity of the bolt amounted to 27.69 kN. Normal stress in the weld amounted to σ⊥_max = τ⊥_max = 72.72 MPa, in the vertical weld to σ⊥= τ⊥= 63.34 MPa and tangent stress amounted to τ|| = 4.37 MPa. The results allowed us to implement minor changes such as increasing the distance between the bolt and the edge and decreasing the size of the fillet welds. The design is fully compliant with the EN 1993-1-8 norm. Using Robot Structural Analysis substantially increased the pace of calculations giving precise and clear outcomes

FUNCTIONAL PLASMA-DEPOSITED COATINGS

The paper focuses on the problem of low adhesion of plasma sprayed coatings to the substrate. The subsequent laser treatment modes and their influence on the coatingsubstrate interface were studied. This allows to decrease the level of met-stability of the coating, thus decreasing its hardness down to 11–12 GPa on the surface and to about 9 GPa on depth of 400 µm. The redistribution of alloying elements through solid and liquid diffusion improves mechanical properties and rises the adhesion up to 450 MPa after remelting and up to 90–110 MPa after laser-aided thermal cycling. At the same time, remelting of coating helps to decrease its porosity down to 1%. The obtained complex of properties also allows to improve wear resistance of coatings and to decrease friction factor

Using program mathcad for solving problems of engineering for the example construction truss

W artykule przedstawiono możliwości wykorzystania programu Mathcad do rozwiązywania wybranych zagadnień ze zbioru zadań z mechaniki technicznej lub wytrzymałości materiałów. Pokazano przykład wyznaczania sił w prętach oraz reakcje podpór konstrukcji kratowej (kratownicy płaskiej) metodą Rittera i metodą równoważenia węzłów. Zauważono, że narzędzie to znacznie ułatwia proces rozwiązywania zagadnień oraz umożliwia szybkie przeanalizowanie zachowania się danej konstrukcji przy różnych obciążeniach.The article presents the possibility of using program Mathcad to solve selected problems from the set of tasks with the mechanics of technical and material strength. An example of determining the forces in the bars and the reactions of the supports in truss structures (plane truss) method Ritter and method of balancing nodes. It was noted that this tool greatly simplifies the process of solving problems and can quickly analyze the behavior of a structure with different loads

Wear resistance of eutectic coating of system Fe-Mn-C-B-Si-Ni-Cr obtained by welding method with use wire powder

W artykule omówiono właściwości tribologiczne powłoki eutektycznej na bazie układu Fe-Mn-C-B-Si-Ni-Cr otrzymanej metodą napawania łukowego w osłonie gazowej GMA z użyciem drutu proszkowego. Badanie przeprowadzono dla próbek z powłoką eutektyczną w układzie trzpień-tarcza podczas ruchu ślizgowego na sucho dla prędkości 0,4 m/s przy przyłożonych obciążeniach 3, 7 i 10 MPa. Materiał przeciwpróbki stal C 45. Po tarciu strukturę i rozkład atomów na powierzchni powłoki eutektycznej badano z użyciem skaningowego mikroskopu elektronowego SEM. Na podstawie uzyskanych wyników badań zaproponowano mechanizm zużycia opracowanych materiałów kompozytowych eutektycznych. W procesie tarcia występuje segregacja atomów C, B i Si na powierzchniu tarcia, spowodowana termodyfuzją, aktywizowana cyklicznym rozgrzewaniem powierzchni tarcia. Wskutek tribosyntezy powstają fazy nanokrystaliczne, które powodują zwiększenie odporności na zużycie kompozytów eutektycznych. Mechanizm tarcia jest utleniający.Wear resistance of eutectic coating of system Fe-Mn-C-B-Si-Ni-Cr obtained by welding method with use wire powder was studied. The coating were obtained by gas metal arc welding GMA with use of wire powder. Pin-on-disk dry sliding wear tests at sliding speeds 0,4 m/s and under loads 3, 7, 10 MPa were conducted for pin specimens with eutectic coatings. Material of counter-sample was steel C 45. After friction structure and distribution of atoms in the eutectic coatings due to wear was studied by scanning electron microscopy (SEM). Segregation of the C, B and Si caused of the thermal diffusion, activated by of the friction heating of the friction surface. Tribosyntese arise as a result of nanocrystalline phase, which increase the wear resistance of composites eutectic. The mechanism of friction is oxidizin

Studium odporności na zużycie wzmacnianych kompozytów poliamidowych dla metalowo-polimerowych przekładni zębatych

An experimental study of the wear resistance of two dispersion-filled composite materials based on polyamide used in metal-polymer gear drives with a 30% volume content of short glass or carbon fibres was performed according to the technique proposed by the authors. As a result of tribotests in the “pin-disk” scheme, the mass wear of these composites was determined under dry friction conditions for steel 45 at room temperature in the range of contact pressures of 10–40 MPa, as well as the kinetics of the coefficient of sliding friction and the contact temperature of the tribosystem elements. It was established that polyamide strengthened by carbon fibres has almost four times higher wear resistance in comparison with a polyamide filled with glass fibres. The wear resistance characteristics that are the basic parameters of the tribokinetic wear model are calculated, using the durability of the straight spur metal-polymer gear drive on the basis of the original calculation method. It was established that gear drive durability with a pinion or a wheel reinforced with carbon fibres is more than eight times the durability of gear drive with gear wheels from polyamide filled with glass fibres. The gear drive durability with the steel pinion and the composite gear wheel increases in proportion to the gear ratio as compared to the gear drive with the composite pinion and the steel wheel. The change in the maximum contact pressures in the mesh interval was calculated.Według metodyki autorskiej przeprowadzono badania doświadczalne odporności na zużycie dwóch materiałów kompozytowych na podstawie poliamidu wypełnionego 30% krótkimi dyspersyjnymi włóknami szklanymi oraz węglowymi stosowanego w zębatych przekładniach metalowo-polimerowych. W wyniku badań tribologicznych wg schematu „pin of disk” zostały oszacowane zużycia masowe przy tarciu suchym materiałów pary tribologicznej kompozyt – stal C45 w temperaturze pokojowej w zakresie nacisków stykowych 10–40 MPa. Została też przebadana kinetyka zmiany współczynnika tarcia ślizgowego oraz temperatury obu elementów układu tarciowego w strefie okołostykowej w trakcie eksperymentu. Ustalono, że poliamid wzmocniony włóknami węglowymi ma prawie czterokrotnie wyższą odporność na zużycie niż wzmocniony włóknami szklanymi. Następnie obliczono dla przebadanych par tribologicznych ich wskaźniki (charakterystyki) odporności na zużycie jako bazowe parametry tribokinetycznego modelu matematycznego zużywania, na podstawie których przeprowadzono wg autorskiej metody obliczeniowej oszacowanie resursu walcowej metal – polimerowej przekładni o zębach prostych. Określono, że trwałość przekładni z zębnikiem lub kołem zębatym wzmocnionym włóknem węglowym (zębnik lub koło zębate) przewyższa trwałość przekładni wzmocnionej włóknem szklanym powyżej ośmiu razy. Trwałość przekładni ze stalowym zębnikiem i kompozytowym kołem zębatym jeszcze wzrasta proporcjonalnie w porównaniu z przekładnią z zębnikiem kompozytowym i kołem stalowym. Przebadano zmianę maksymalnych nacisków stykowych w cyklu zazębienia