Sunny Zafar

On Friction and Wear Behavior of WC-12Co Microwave Clad

In the present work, the friction and wear behavior of microwave-clad WC-12Co cermet was examined using a pin-on-disk tribometer as per ASTM G99. Microwave clads were tested against an EN-31 countersurface in unlubricated conditions. The WC-12Co clads were developed using an industrial microwave applicator at 2.45 GHz and 1.4 kW. The influence of varying normal load on the tribological characteristics of the microwave-induced clads have been investigated. Responses of the WC-12Co microwave clads and AISI 304 stainless steel substrate were monitored and the resulting wear was subsequently analyzed in terms of wear rate, pressure–velocity–time (p-v-t) characteristics, and friction coefficient. The worn surfaces of the WC-12Co microwave clad and AISI 304 substrate were studied using scanning electron microscope. Wear debris was analyzed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The developed clads exhibit significant resistance to wear attributable to the microwave-induced dense microstructure and material properties. The wear rate and friction coefficient were reduced by 67 and 56%, respectively for WC-12Co microwave clad compared to that of the AISI 304 substrate.

Dry erosion wear performance of Inconel 718 microwave clad

Abstract This paper reports on the dry erosive wear performance of Inconel 718 clads deposited on SS-304 substrates through microwave hybrid heating technique. Clads were deposited using a domestic microwave applicator at 2·45 GHz and 900 W. The microstructural observations of the Inconel 718 clad indicate good metallurgical bonding with the substrate and revealed no visible interfacial cracking. The microhardness of the clads was assessed using a Vicker’s microhardness tester and the average microhardness in the clads was 564±22 HV. Erosive wear performance of the clads was evaluated using an air jet erosion test setup as per ASTM G76 standard. The effect of varying impact angle was studied; the results have been discussed with the help of SEM images of the worn surfaces. It was observed that the improved erosive performance of the Inconel 718 clads was due to presence of strengthening intermetallic phases (Ni3Ti, Ni3Al) in the tough Ni–Fe–Cr matrix.

Influence of heat treatment on microstructure of Inconel 718 microwave clads

In the present work, Inconel 718 powder was deposited on mild steel (MS) substrate using microwave cladding in an industrial multimode microwave applicator at 2.45 GHz and 1.1 kW. The clads were then subjected to various heat treatments, like, direct aged (DA), solution treated and aged at 981°C (981STA) and solution treated and aged at 1080°C (1080STA) in order to improve their microstructure and mechanical properties. The Inconel 718 clads were characterised, in both, as-deposited and heat-treated conditions in terms of microstructure, elemental distribution and microhardness. Microstructure of the as-deposited and DA specimens exhibited the presence of Laves phases. The 981STA and 1080STA treated specimens demonstrated partially dissolved and completely dissolved Laves phases, respectively. The microhardness of the 1080 STA heat-treated clads was two times higher compared to the as-deposited Inconel 718 clad attributed to the precipitation of strengthening phases in the 1080 STA clad layer.

Development and mechanical characterization of microwave-cured thermoplastic based natural fibre reinforced composites

In the present work, polypropylene (PP)- and polyethylene (PE)-based composites were cured using microwave energy with 15% weight percentage of jute and kenaf fibres. The detailed mechanism of microwave curing of the composites has been discussed with suitable illustrations. The mechanical characterization of the microwave-cured composites was carried out using various tests. The scanning electron microscope (SEM) fractographs were used to study the mechanisms of failure. The ultimate tensile strength of various microwave-cured composites was in the range of 44–50 MPa. The interlaminar shear strength of the PP-based composites was 62% higher than the PE-based composites. The impact energy of the microwave-cured composites was in the range of 18–24 kJ. The mechanical performance of the microwave-cured composites was comparable to the composites obtained through traditional manufacturing routes.

Influence of microwave power on mechanical properties of microwave-cured polyethylene/coir composites

ABSTRACT The present work deals with investigating the influence of microwave power on mechanical properties of 20 wt.% coir reinforced high-density polyethylene (HDPE) composites. Chopped coir/HDPE composites were fabricated using various microwave power levels (360 W, 540 W, 720 W and 900 W). The XRD analysis of the specimens reveals that crystallinity index in various specimens was in the range of 79.54% to 84.59%. The specimen cured at 360 W exhibited a maximum tensile strength of 29.5 ± 1.5 MPa, which is 28.26% greater than composite cured at 900 W (23 ± 1.5 MPa). Flexural strength of specimen cured at 360 W was maximum (37.74 ± 2 MPa).