Sarbjeet Kaushal

Processing and characterization of composite cladding through microwave heating on martensitic steel

The composite wear resistant cladding of nickel-based powder matrix and 10% SiC powder as reinforced was developed through microwave hybrid heating on martenisitic stainless steel (SS-420) substrate. The development of the clad has been carried out by using a domestic microwave applicator of frequency 2.45 GHz and 900 W power level. The microstructural and mechanical characterizations of the developed clad were carried out by using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Vicker’s microhardness analysis. Results revealed that clads of approximately 1.25 mm thickness were developed with significantly low porosity (∼1.10%). The scanning electron microscopic results show that the microstructure of clad exhibits typical cellular-like structure. The metallurgical bonding between clad and substrate surface was obtained with partial dilution. The complex carbides of chromium and silicides of chromium, iron, and nickel phases were identified in the clad region by XRD study, which may enhance the Vicker’s microhardness of the clads significantly. The average Vicker’s microhardness of the developed clad was in the range of 652 ± 90 HV.

On surface modification of austenitic stainless steel using microwave processed Ni/Cr3C2 composite cladding

ABSTRACT In the present work Ni-based + 20% Cr3C2 composite clads were developed on SS-304 austenitic stainless steel through microwave hybrid heating technique. Experimental trials were conducted inside a domestic microwave applicator at 2.45 GHz and 900 W. The developed microwave composite clads were characterised through SEM/EDS, XRD and Vicker’s micro-hardness tests. Further tribological wear behavior of the so developed clad was investigated using pin-on-disc type tribometer under dry sliding wear conditions. Microstructural analysis revealed the uniform dispersion of Cr3C2 particles inside the Ni matrix in the form of cellular-like structure. The presence of FeNi3, NiSi, Cr3Ni2 and chromium carbide (Cr3C2) was confirmed from the XRD analysis, which contributes to the increase in micro-hardness of the composite clad. The average value of micro-hardness of the developed clads was found to be 450 ± 55 HV. The microwave-processed clad exhibits three times more wear resistance than SS-304 substrate.

An approach for functionally graded cladding of composite material on austenitic stainless steel substrate through microwave heating

In the present work, functionally graded clads of Ni-SiC material have been developed on austenitic stainless steel (SS-304) substrate through 2.45 GHZ domestic microwave applicator. The functionally graded clads were processed by the concept of hybrid heating with varying exposed microwave power levels from 180 to 900 W. The optimum exposure time of 900 W microwave power was varied with compositional gradient and it is from 300 s to 420 s. The maximum thickness achieved for functionally graded clads was 2 mm at optimum exposure power and time. The microstructural analysis of developed clads reveals that the partial mutual diffusion between each successive layer took place and it confirms the metallurgical bonding in between. The typical flower like structure of Ni-matrix has been observed in clads where the SiC particles were uniformly dispersed. The maximum functionally graded clads micro-hardness of 1020 ± 30 HV were achieved.

On processing of Ni-WC based functionally graded composite clads through microwave heating

ABSTRACT Present study focuses on the development of four layered functionally graded clads (FGC) of Ni-WC based composite material on AISI 304 substrate through microwave heating route. Experimental trials were conducted inside a microwave applicator of domestic type at frequency range of 2.45 GHz. The optimal exposure time of 900 W microwave power was varied with compositional gradient and it was from 300 to 360 s. The mechanism of FGC formation through microwave heating was explained and developed FGC was subjected to mechanical and microstructure characterizations. The results of micro-structural analysis revealed that the FGC of ∼1.8 mm thickness was produced and was free from any type of interfacial cracks and visible porosity. It was observed that WC particles were randomly dispersed in the nickel matrix. XRD study revealed the formation of inter-metallics, such as NiW4, NiSi, and Cr23C6. Maximum value of microhardness was observed in the top FGC layer and was 880 ± 30 HV.

On Processing of Ni–WC8Co-based Composite Clads on Austenitic Stainless Steel Through Microwave Energy

In the present investigation, composite clads of Ni + 20% WC8Co and Ni + 30% WC8Co were developed on austenitic stainless steel (SS-316) using microwave energy. Experiments trials were carried out inside a domestic microwave oven with a frequency range of 2.45 GHz and variable power level of 180–900 W. The exposure time and power level for developing clads were optimized. The microwave processed clads were further characterized through SEM/EDS, XRD, and measurement of Vicker’s microhardness. Microstructural results revealed that the clads of approximately 0.7 mm thickness were free from any type of interfacial cracks and voids. WC particles were uniformly distributed inside soft Ni matrix. The presence of NiSi, Co3W3C, Fe6W6C, NiW, NiCr, and FeNi3 phases was observed during phase analysis of developed composite clads. Microhardness of the Ni + 20% WC8Co and Ni + 30% WC8Co was found to be 810 ± 75 and 923 ± 65 HV, respectively.

Surface modification of SS-316L steel using microwave processed Ni/WC based composite clads

In the present investigation, the claddings of Ni/WC based composite powder were developed on SS-316L steel through microwave hybrid heating method. The experimental trials were carried out inside a domestic microwave oven working at 2.45 GHz and 900 W. The so developed composite clads were characterized using XRD, Vicker’s microhardness measurement, and SEM/EDS. The presence of different phases like Co3W3C, NiW, FeNi3, NiSi was confirmed by XRD analysis. Microstructural analysis revealed that the clad of approximately 0.6 mm thickness was developed with no interfacial cracks and negligible porosity. The WC particles were uniformly distributed in the form of cellular structure inside Ni matrix. The average Vicker’s microhardness value of the clad section was observed as 925±50 HV, which is three times that of the SS-316L substrate.In the present investigation, the claddings of Ni/WC based composite powder were developed on SS-316L steel through microwave hybrid heating method. The experimental trials were carried out inside a domestic microwave oven working at 2.45 GHz and 900 W. The so developed composite clads were characterized using XRD, Vicker’s microhardness measurement, and SEM/EDS. The presence of different phases like Co3W3C, NiW, FeNi3, NiSi was confirmed by XRD analysis. Microstructural analysis revealed that the clad of approximately 0.6 mm thickness was developed with no interfacial cracks and negligible porosity. The WC particles were uniformly distributed in the form of cellular structure inside Ni matrix. The average Vicker’s microhardness value of the clad section was observed as 925±50 HV, which is three times that of the SS-316L substrate.

Processing of Ni–WC–Cr3C2-based metal matrix composite cladding on SS-316L substrate through microwave irradiation

The present paper reports on the development of metal matrix composite clads of Ni–WC–Cr3C2-based materials through microwave heating route. In this study, metal matrix composite clads were deposited on austenitic stainless steel (SS-316 L) inside a multimode-type domestic microwave oven. Experiment trials were carried out at a microwave power of 900 W and frequency of 2.45 GHz. The optimal exposure time for processing of metal matrix composite clads was varied from 60 to 360 s. The microstructural analysis of processed clads revealed that the metal matrix composite clads of approximately 0.85 mm thickness were free from any type of voids and cracks. The WC and Cr3C2 particles were dispersed inside the Ni matrix. The phase analysis results revealed the formation of Cr7Ni3, NiC, Fe6W6C, Co3W3C4, FeNi3, NiW phases inside the clad layer. The formation of hard carbide phases resulted in higher microhardness of the clad layer. The average value of Vicker’s microhardness was observed to be 503 ± 34 HV, which is almost 1.6 times that of the substrate.

An approach for developing nickel–alumina powder-based metal matrix composite cladding on SS-304 substrate through microwave heating:

In the present study, metal matrix composite clads of nickel–alumina powder-based material have been produced on austenitic stainless steel (SS-304) substrate using microwave heating at 2.45 GHz frequency. A concept of hybrid heating was used to process metal matrix composite clads at exposure power level of 900 W. The exposure time for developing metal matrix composite clads was varied from 60 to 300 s. The clads of average thickness 0.6 mm were successfully developed at an optimized exposure time of 300 s. The microstructural analysis of microwave processed clads reveals the uniform dispersion of alumina powder particles inside nickel matrix. The developed clads were free from any type of interfacial cracks and were metallurgically bonded with SS-304 substrate. X-ray diffraction study confirmed the presence of alumina powder, FeNi3 and chromium carbide phases, which contributed to the increase in micro-hardness of developed clad. Clad micro-hardness was found to be four times that of austenitic stainless steel, which makes it suitable for anti-wear applications.