Functionally Graded Coatings of Carbon Reinforced Carbon by Physical and Chemical Vapour Deposition (PVD and CVD)

Maile, Karl; Berreth, Karl; Lyutovich, A.

doi:10.4028/www.scientific.net/msf.492-493.347

Cited by 7 publications

(3 citation statements)

References 5 publications

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“…Due to the increased Si content the surface layer showed a modified microstructure with improved oxidation behaviour. The excess of Si was converted to Si 3 N 4 using NH 3 [15]. Si or codiffusion for Al-Si coatings were developed at 600 8C [16].…”

Section: Methodsmentioning

confidence: 99%

Silicon surface treatment via CVD of inner steel tube surfaces

Berreth

Maile

Lyutovich

2005

Materials and Corrosion

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Inner surfaces of steel tubes should be protected against corrosion and oxidation by a coating in order to assure optimised application in power plants and the chemical industry. Since the silicon content in chromium alloyed steels improves the oxidation protection. Chemical vapour deposition (CVD) of Si has been investigated for martensitic 9% chromium steel (T91). The surface treatment was performed as a combined process of CVD at atmospheric pressure with heat treatment in a chemical atmosphere with high frequency heating (HF), automated with a Simatic PCS7. The Si out of SiCI 4 diffused into the steel lattice of the substrate surface. As a result, the Si-content near the surface layer increased as a ferrite layer which did not transform to martensite during heat treatment. The excess of Si was converted to Si 3 N 4 using NH 3 . This improves the anti-oxidation behaviour. The physical and chemical properties of the modified surfaces were investigated and characterised using the SEM, EDX, electron microprobe and X-ray diffraction methods. The deformation capacity of a coated specimen was proven by means of hot tensile tests. It could be determined that in the ferritic layer Fe is substituted by Si with a maximum concentration of approx. 5%, however the Cr content was almost constant.

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Section: Methodsmentioning

confidence: 99%

Silicon surface treatment via CVD of inner steel tube surfaces

Berreth

Maile

Lyutovich

2005

Materials and Corrosion

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“…The benefit of FGM is overcoming the limitations of dissimilar metal joints resulting from interfacial stresses or chemical incompatibility by a continuous gradient while combining the respective advantages of different materials, resulting in superior part properties. According to literature, production technologies, such as casting, sintering, powder metallurgy, diffusion bonding, thermal spraying, and physical or chemical vapor deposition, may be used for manufacturing FGM [1][2][3][4][5]. Each of the mentioned technology shows advantages and limitations.…”

Section: Introductionmentioning

confidence: 99%

Multi-material additive manufacturing-functionally graded materials by means of laser remelting during laser powder bed fusion

Schmidt,

Jensch,

Härtel

2023

Front. Mech. Eng.

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Many processes may be used for manufacturing functionally graded materials. Among them, additive manufacturing seems to be predestined due to near-net shape manufacturing of complex geometries combined with the possibility of applying different materials in one component. By adjusting the powder composition of the starting material layer by layer, a macroscopic and step-like gradient can be achieved. To further improve the step-like gradient, an enhancement of the in-situ mixing degree, which is limited according to the state of the art, is necessary. In this paper, a novel technique for an enhancement of the in-situ material mixing degree in the melt pool by applying laser remelting (LR) is described. The effect of layer-wise LR on the formation of the interface was investigated using pure copper and low-alloy steel in a laser powder bed fusion process. Subsequent cross-sectional selective electron microscopic analyses were carried out. By applying LR, the mixing degree was enhanced, and the reaction zone thickness between the materials was increased. Moreover, an additional copper and iron-based phase was formed in the interface, resulting in a smoother gradient of the chemical composition than the case without LR. The Marangoni convection flow and thermal diffusion are the driving forces for the observed effect.

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“…These methods have seen improvements in design, development, and uses to overcome challenges encountered by traditional methods. Various fabrication processes are centrifugal casting [10], powder metallurgy (PM) [11], solid free foam (SFF) [12], physical and chemical vapor deposition (PVD/CVD) [13], 3D printing [14], electrophoretic deposition (EPD) [15], and friction stir processing (FSP) [16], etc.…”

Section: Introductionmentioning

confidence: 99%

Functionally graded AZ91/WC nanocomposite fabricated via friction stir processing using a novel way

Subhi

Abdulkareem

Hussein

2022

J min metall B Metall

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In this work, functionally graded AZ91/WC nanocomposites were produced by a novel multi-stage reduction of chamber diameter method. The WC nanoparticles were packed in chambers having graduated diameters and friction stir processing was applied using tool with four-sided fluted probe. The functionally graded nanocomposites were obtained using different tool rotational speeds (830, 960 and 1160 rpm) with a constant traverse speed and plunge depth of 40 mm/min and 0.1 mm, respectively. The characteristics of the functionally graded samples and AZ91 Mg alloy were evaluated utilizing optical and scanning electron microscopes, and energy dispersive spectroscopy as well as other tests such as hardness, pin on disc wear and potentiodynamic polarization tests. The results showed that ?-Mg refining and graded distribution of WC nanoparticles were enhanced with augmenting tool rotational speed. The hardness increased slightly with augmenting tool rotational speed. The results also revealed that the wear rate was decreased and corrosion resistance was improved by adding WC nanoparticles. Abrasive wear mode was the main mode of material removal during dry sliding while cracks and pits were the main features of corroded surface.

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Functionally Graded Coatings of Carbon Reinforced Carbon by Physical and Chemical Vapour Deposition (PVD and CVD)

Cited by 7 publications

References 5 publications

Silicon surface treatment via CVD of inner steel tube surfaces

Silicon surface treatment via CVD of inner steel tube surfaces

Multi-material additive manufacturing-functionally graded materials by means of laser remelting during laser powder bed fusion

Functionally graded AZ91/WC nanocomposite fabricated via friction stir processing using a novel way

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