Effect of Heat Treatment on Microstructure and Corrosion Resistance of Ni-P/BN(h) Composite Coatings

2011 ◽  
Vol 239-242 ◽  
pp. 3362-3366
Author(s):  
Cheng Zhang Peng ◽  
Ling Ling Zhu ◽  
You Ming Chen
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Stable State ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Pulse Electroplating ◽  
Heat Treated ◽  
Precipitated Phases

The Ni-P/ BN(h) composite coatings were prepared by pulse electroplating,and were heat treated at temperature of 200～400°C.The microstructure of the composite coatings was identified by X-ray diffraction,the corrosion behavior of the composite coatings in 3.5%NaCl and 10%H2SO4 solutions was investigated by the linear polarization measurements and scanning electron microscope (SEM).The results show that the as-deposited is an amorphous structure,the precipitated phases are Ni12P5 and Ni5P2 metastable state phases when heat treatment temperature is below 300°C,the precipitated phases is Ni3P stable state phase heat-treated at 400°C，the composite coating was crystallized in great degree.Both the as-deposited and heat treated composite coatings revealed best corrosion resistance in 3.5%NaCl and 10%H2SO4 solutions.

Characterization of Ni-P and Ni-P-Al2O3 Heat Treated Layers

2017 ◽  
Vol 1143 ◽  
pp. 26-31
Author(s):  
Lucica Balint ◽  
Gina Genoveva Istrate
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coatings ◽  
Treatment Temperature ◽  
Initial State ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Before And After

Research has shown the relationship among hardness, usage and corrosion resistance Ni-P-Al2O3 composite coatings on steel support heat treated. The electroless strips were heat treated at 200°C, 300°C, 400°C, 500°C and 600°C. Further studies on corrosion, hardness and usage revealed changes in properties, compared to the initial state, both on the strips coated with Ni-P and the ones coated with Ni-P-Al2O3 composite. The samples have been studied before and after the heat treatment via Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Analysis (EDX) and X-Ray Diffraction (XRD). The results show that untreated Ni-P layers exhibit strong corrosion resistance, while hardness and usage increase with heat treatment temperature, with a peak at 400 °C. Using suspended particles co-deposition, led to new types of layers, some with excellent hardness and usage properties. Corrosion resistance increase with heat treatment. Coating layers can be adjusted to the desired characteristics, by selecting proper parameters for the expected specific results.

Morphology of Carbon Micro-Coils

2004 ◽  
Vol 449-452 ◽  
pp. 205-208
Author(s):  
M. Fujii ◽  
S. Motojima
Keyword(s):  
Heat Treatment ◽  
Lattice Structure ◽  
Diffraction Method ◽  
Chemical Vapor ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Higher Temperature

The double helical carbon micro-coils were obtained by chemical vapor deposition. As-grown carbon micro-coils with amorphous structure were heat-treated at various temperatures up to 3000°C . By heat treatment, the shape of the coils was not changed. The morphology of these coils was observed in detail using electron microscope. The lattice structure was analyzed by X-ray diffraction method. Heat treatment temperature dependence of the magnetoresistance and the measurement of Raman spectra suggest that the coils heattreated at higher temperature are more highly graphitized.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Ni-B-W-Mo COATING DEPOSITED BY ELECTROLESS METHOD

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Sodium Molybdate ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Heat Treated ◽  
Electroless Coatings

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.

Research on Properties of Amorphous Cr-C Alloy Coating in Crystallization Evolution

2012 ◽  
Vol 184-185 ◽  
pp. 1175-1180
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Bi Xue Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Adhesion Force ◽  
Alloy Coating ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Proper Values ◽  
Peak Value

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.

Investigation on the Influence of Precipitated Phase on Corrosion Resistance of the Ni-Based Alloys

2012 ◽  
Vol 184-185 ◽  
pp. 1038-1043
Author(s):  
Xue Hui Zhao ◽  
Zhen Quan Bai ◽  
Yao Rong Feng ◽  
An Qing Fu
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
Grain Boundaries ◽  
Aging Treatment ◽  
Treatment Temperature ◽  
Different Temperatures ◽  
Metallographic Observation ◽  
Precipitated Phases

The influence of precipitated phases in Ni-based alloys during solid solution aging treatment on the performance of Ni-based alloys was investigated by means of metallographic observation, scanning electron microscope (SEM), and transmission electron microscope (TEM). The variation of microstructure and resultant phases as a result of solid solution aging treatment at different temperatures was discussed. The results show that the heat treatment temperature has significant influences on the type as well as quantity of precipitation phases. Lots of phases precipitated at grain boundaries, the distribution of precipitated phases are characterized by mesh-like structure. The corrosion tests results indicate that there is a potential difference between grains and grain boundaries due to the precipitation of chrome carbide at grain boundaries, resulting in pitting corrosion occurred preferentially at grain boundaries, consequently, the corrosion resistance of Ni-based alloys is reduced. In order to enhance the corrosion resistance of Ni-based alloys, it is expected to control the carbon content in a lower range and proper heat treatment process to avoid large amount precipitation of chrome carbide.

scholarly journals Influence of Different Heat Treatment Temperatures on the Microstructure, Corrosion, and Mechanical Properties Behavior of Fe-Based Amorphous/Nanocrystalline Coatings

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 858
Author(s):  
Shenglin Liu ◽  
Yongsheng Zhu ◽  
Xinyue Lai ◽  
Xueping Zheng ◽  
Runnan Jia ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Treatment Temperature ◽  
Annealing Treatment ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Different Temperatures ◽  
Sprayed Coating

Fe-based amorphous/nanocrystalline coatings with smooth, compact interior structure and low porosity were fabricated via supersonic plasma spraying (SPS). The coatings showed outstanding corrosion resistance in a 3.5% NaCl solution at room temperature. In order to analyze the effect of annealing treatment on the microstructure, corrosion resistance and microhardness, the as-sprayed coating was annealed for 1 h under different temperatures such as 350, 450, 550 and 650 °C, respectively. The results showed that the number of oxides and cracks in the coatings presented an obvious increase with increasing annealing temperature, and the corrosion resistance of the coatings showed an obvious reduction. However, the microhardness of coatings showed an important increase. The microhardness of the coating could reach 1018 HV when the heat treatment temperature reached 650 °C. The X-ray diffraction (XRD) results showed that there appeared a number of crystalline phases in the coating when the heat treatment temperature was at 650 °C. The crystalline phases led to the increase of the microhardness.

Characteristics of Electroless Nickel-Phosphorus-Potassium Titanate Whisker Composite Coating

2012 ◽  
Vol 472-475 ◽  
pp. 70-73
Author(s):  
Ya Xu Jin ◽  
Yu Ming Tian ◽  
Qiu Shu Li
Keyword(s):  
Heat Treatment ◽  
Composite Coating ◽  
Composite Coatings ◽  
Electroless Nickel ◽  
Medium Carbon Steel ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Potassium Titanate ◽  
Steel Substrates ◽  
Electroless Ni

Electroless nickel plating with potassium titanate whisker was co-deposited on medium carbon steel substrates. The microstructure of the composite coatings was investigated. The effect of aging temperature on the microstructure of the composite coatings was studied using X-ray diffraction. The results indicate that the composite coatings will turn into crystal state with increasing heat treatment temperature. Experimental results also show that a maximum hardness is achieved for the composite coating after heat treatment at 400°C for 1 hour. The corrosion resistance and tribological properties of the composite coatings are not inferior to those of electroless Ni-P coating.

scholarly journals Corrosion Resistance of Heat-Treated Ni-W Alloy Coatings

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1172
Author(s):  
Magdalena Popczyk ◽  
Julian Kubisztal ◽  
Andrzej Szymon Swinarew ◽  
Zbigniew Waśkiewicz ◽  
Arkadiusz Stanula ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Active Surface ◽  
Active Surface Area ◽  
X Ray Diffraction ◽  
Kelvin Probe ◽  
Research On Evaluation ◽  
Heat Treated ◽  
Electrochemically Active

The paper presents research on evaluation of corrosion resistance of Ni-W alloy coatings subjected to heat treatment. The corrosion resistance was tested in 5% NaCl solution by the use of potentiodynamic polarization technique and electrochemical impedance spectroscopy. Characteristics of the Ni-W coatings after heat treatment were carried out using scanning electron microscopy, scanning Kelvin probe technique and X-ray diffraction. Suggested reasons for the improvement of properties of the heat treated Ni-W coating, obtained at the lowest current density value (125 mA∙cm−2), are the highest tungsten content (c.a. 25 at.%) as well as the smallest and the most homogeneous electrochemically active surface area.

scholarly journals Corrosion resistance of UNS S31803 stainless steel welded joints

2018 ◽  
Vol 24 (2) ◽  
pp. 147
Author(s):  
Paolo Ferro ◽  
Jan-Olof Nilsson ◽  
Franco Bonollo
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Welded Joints ◽  
Heat Treatment Temperature ◽  
Experimental Tests ◽  
Treatment Temperature ◽  
Gas Composition ◽  
Shielding Gas ◽  
Heat Treated

<p>The corrosion resistance of duplex stainless steel welded joints is affected by different parameters such as filler metal chemical composition, heat input, shielding gas composition and post welding heat treatment temperature. In most cases such parameters interact with each other so that it is very difficult to foresee their effect on corrosion resistance of welded joints without specific experimental tests. In this work the best combination of shielding gas composition and post welding heat treatment temperature that guarantees the corrosion resistance of the joint according to ASTM  A932, method C, was found.  Two shielding gases were tested during welding, Ar (100%) and a mixture of Ar (87%), He (10%) and N (3%), while the solution temperatures were 1050 °C and 1070 °C.  It was found that only the samples welded with the mixture of Ar (87%), He (10%), N (3%) as shielding gas and solution heat treated at 1070 °C passed the corrosion test completely.</p>

Study on Preparation of SiO2 Optical Fiber Preform by SG Method

2011 ◽  
Vol 299-300 ◽  
pp. 489-492
Author(s):  
Hui Tang ◽  
Ji Peng Zhang ◽  
Feng Gu ◽  
Feng Chun Wang ◽  
Ji Hua Wang
Keyword(s):  
Heat Treatment ◽  
Optical Fiber ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Parent Material ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Fiber Preform ◽  
X Ray ◽  
Ft Ir

SiO2 optical fiber preform, the parent material in manufacturing optical fiber, plays an important role in the properties of optical fiber. In this paper, SiO2 dry gel was prepared by Sol-Gel method. According to this method, the gel was formed by hydrolyzing tetraethyl orthosilicate(TEOS) with hydrochloric acid and ammonia water, and the SiO2 dry gel was obtained by heat treatment of the gel at different temperature. The structure of the dry gel as prepared was characterized by X-ray Diffraction(XRD), Fourier Transform Infrared Spectroscopy(FT-IR) and Scanning electron microscope(SEM). As a result, amorphous structure is proved. Meanwhile, microscopic cracks are found to be decreased by adding formamide and increased when the heat-treatment temperature is above 75°C.

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