Characterization of Titanium-Based Films Deposited by DC Sputtering Reactive on AISI 1018 Steel

The coated surfaces first layer Ti and second layer TiO2 as coating Nanostructured thin films of using DC sputtering on structural steel (AISI l018) and study characterization of coating SEM/EDS inspection shown a clearly perfect incorporation of layer by dc sputtering a granular structure of the layer with a variable hemisphere’s forms varied from 33 to 46 nm in size. X-XRD test complete for specimen indicates was found anatase phase titanium dioxide, the resulted coating layer of the target of Ti powders gives different morphology from the Ti layer alone The Specimens roughness average of coated Ti and TiO2with respectively was 4.831nm, 7.93 nm. Found that titanium layer will show a major part in increasing the bonding with improving the bond between the substrate steel AISI (1018) and the titanium oxide layer. The Vickers hardness increases when the coating with a layer of titanium with an oxygen content of ceramic layer is formed from 192.3 HV to 227 for Ti as well as important increase was detected in the Tio2 coating to 240 HV. In addition, Ti and Tio2 thin layer considered as a good barrier for hydrogen permeation through steel structure especially at cathode protection in pipelines.

Research on high-temperature oxidation resistance, hot forming ability, and microstructure of Al–Si–Cu coating for 22MnB5 steel

High-temperature oxidation resistance, hot formability, element distribution, and microstructure of Al-10% Si-(0.5–3.0%)Cu coating were investigated by means of glow discharge spectroscopy, optical microscope, scanning electron microscope, and energy-dispersive spectroscopy. Results show that the addition of Cu can increase high-temperature oxidation resistance above 950°C and improve hot formability so that no crack spreads into substrate steel as hot forming at 33.3% strain. Oxidation film structure is continual and compacting, and Si highly concentrates in the surface layer. The distribution of Cu has skin effect with peaking content 8.2% in the surface layer. After hot stamping, Al and Si diffuse into substrate steel, and Cu diffuses from inner to outer coating. Al–Si–Cu coating has smoother surface, straighter diffusion layer, and finer metal compound than Al–Si coating. Surface and diffusion layers are identified as aluminum oxide, Si-rich, and Cu phase and Al7SiFe2, Al3Fe, and CuAl3, respectively. Al-rich phase and the metal compound are composed of α-Al dissolving Fe, Si, and Cu and Al–Si matrix, Cu3Al, respectively.

Cavitation Erosion-Corrosion Resistance of Deposited Austenitic Stainless Steel/E308L-17 Electrode

The ultrasonic vibratory test was carried out to evaluate the cavitation erosion/corrosion resistance of welded-deposited austenitic stainless steel/E308L-17. Three layers of the E308L-17 electrode were deposited onto AISI 1040 substrate utilizing Shielded Metal Arc Welding (SMAW) process. The eroded surfaces of the E308L welded deposit/coating and AISI 1040 substrate steel have been analyzed by evaluating surface topography, as well as scanning electron microscope (SEM) micrographs. In addition, the cumulative weight loss and erosion rate curves were attained to evaluate the cavitation resistance of the tested materials. The cavitation results showed that the E308L-17 deposited stainless steel has lost about 15 mg as a cumulative weight, while the loss of AISI 1040 substrate was about 123 mg. This is equal to 0.12% and 1.0% of the original test specimen weight for the E308L-17 and AISI 1040, respectively. Consequently, E308L-17 austenitic stainless steel can be effectively used as a protective material for surfaces exposed to cavitation wear, since the AISI 1040 substrate has been enhanced by 8 times using E308L stainless steel.

Developing technology of fabrication of functional nanostructured coatings on wear- and corrosion-resistant alloy based on the Cu–Ni system

The paper presents complex studies of nanostructured powder of Cu-Hf-BN alloy system and functional wear and corrosion-resistant coatings based on It are presented. A technology for applying a composite nanostructured coating of the Cu-Ni-Zr-Cr-Hf-BN system onto a steel substrate (steel Kh18Yu5S) was developed using supersonic cold and microplasma deposition techniques. The coatings have elevated level of microhardness (up to 32 GPa), adhesive strength (more than13 MPa), resistance to stress-corrosion crackingand a wide range of operating temperatures from 850 to –196°C.

Fatigue behavior of 590MPa Tensile Strength galvanneal coated sheet steel laser welded blanks

The use of Laser Welded Blanks (LWBs) with different grade/gauge combinations in automotive body structures is well established; however, the acceptance of LWBs in fatigue critical chassis and underbody components has been slower because of lack of reliable models for durability assessment of laser welded joints (LWJ). Most prior fatigue studies of LWBs are carried out in tension - tension loading mode, making it difficult to relate it to the cyclic deformation and fatigue behaviors of the substrate steel grade. In contrast, in this study, LWJ is conceptualized as a "notch" to estimate the local stresses from the strain - life data of the parent grade and the fatigue notch concentration factor (Kf) is estimated from the nominal stress values of LWJ. The method is illustrated with strain controlled fatigue data for 1.4 mm galvanneal coated 590 MPa steel and fully reversed, fatigue data for homogeneous and heterogeneous LWB combinations. The results indicate that for both homogeneous and heterogeneous LWJ configurations, Kf increases with fatigue life, but tends to saturate at life levels greater than about million cycles. Considering 105 cycles to failure as an example, Kf is estimated as 1.07 for the homogeneous and 1.25 for the heterogeneous combinations.

The Influence of PVD Coatings on the Wear Performance of Steel Dental Curettes

The wear properties of steel dental curettes coated with wear resistant Diamond Like Carbon (DLC) and metal nitride coatings deposited by Physical Vapor Deposition (PVD) were studied by using a customized mechanical device simulating motion and load of dental curettes against human teeth. The wear surfaces were studied by optical microscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and Nanoindentation. Rockwell indentation testing was used to evaluate the coating adhesion. With the optimized combination of substrate steel and wear resistant coating reduction of 80% in the wear of instruments could be achieved.

Heat Treated and As-Plated Electroless Duplex Ni-P/Ni-B Coatings: Evaluation of Hardness and Wear Resistance

The present work deals with the formation of NiP/NiB duplex coatings by electroless plating and evaluation of their hardness and wear resistance. The duplex coatings were prepared with Ni-P as the inner layer. To analyze the structure of the coatings, XRD analysis was carried out. According to the results, NiP and NiB coatings are amorphous in their as-plated condition and after applying heat-treatment at 450 °C for 1 h, both NiP and NiB coatings crystallize and produce nickel, nickel phosphide and nickel borides in the coatings. To determine the surface morphology and cross-section characteristics of the coatings, SEM observations were carried out and concluded that duplex coatings are uniform and good coherent exists between the duplex layers and the coatings are also connected closely to the substrate. The hardness of electroless nickel duplex coatings increased with applying heat treatment and reached maximum value at coatings annealed at 400 °C. To analyze the tribological properties, pin-on-disc tests were carried out. The wear track patterns on the coatings and on Al2O3balls were then examined by optical microscopy and EDS. The friction coefficient and wear rate of the coatings were lower than the substrate steel. Friction coefficient decreased from 0.43 to 0.36 and wear resistance decreased from 11.3 to 6.4 by applying heat treatment at 450 °C for 1 h to duplex coatings.

Study of Laser Cladded Layers Structure Applied in Practice

The aim of this paper was the study of laser cladded layers applied in practice from the view of the internal structure of the material changes. In the process of cladding the laser beam was used as the heat source to melt and fuse the cladding alloy LS 30 onto the substrate - steel EN 1.2379.The filler material - wire diameter was 0.4 mm and the maximum height of the coating was 0.3 mm. The basic material was in minimal heat treated, in a very narrow intermediate layer with the character of diffusion joint. The cladded layers were evaluated for resistance to abrasive wear and topography of layers was performed. The proposed technology and the filler material have impact on the topography and roughness of the resulting layers.

Erosion Characteristics of HVOF Developed Cr3C2-NiCr and WC-Co Coatings

Erosion behavior of the high velocity oxy fuel (HVOF) deposited Cr3C2-NiCr and WC-Co coatings on boiler tube steels was evaluated. The solid particle erosion study was conducted, using an air jet erosion test rig at a velocity of 26 m/s and impingement angles of 300 and 900, on uncoated as well as HVOF spray coated boiler tube steels at 250°C. The coatings are significantly harder than the substrate steel and less porous. Scanning electron microscopy (SEM) technique was used to analyze the eroded surface. Mass loss of the coatings was found higher than the boiler tube steel.