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This work presents the effect of rotary speed (RS) and traverse speed (TS) on channel characteristics and weld tensile strength during simultaneous channeling and friction stir welding of dissimilar aluminium alloys 6082 and 2024. TS had discernible effect on the location of channels and shifted the same from advancing side to retreating side of weld joint. The effect of TS on channel area was found reverse to that of RS up to mid value of investigated range and beyond that they followed the same trend. RS had more dominating effect on the channel area than TS. The effect of TS and RS on channel perimeter was identical to that on channel area. It is possible to control the shape and size of channels and also their location by selecting proper combination of processing parameters during simultaneous friction stir channelling and welding of dissimilar aluminium alloys.

In recent years, increasing demand for biodegradable lubricants has been observed in precision machining owing to ISO 14000, which draws more attention toward the operator’s health and environmenta...

Nowadays, Minimum Quantity Lubrication (MQL) technique with eco-friendly groundnut oil is adopted in precision machining to tackle the operator health and environmental issues owing to petroleum based cutting fluid. The effectiveness of this technique depends on mixture quality of MQL mist. Hence, the objective of present work is to optimize the MQL mist parameters i.e. air pressure (P), flow rate (Q), and stand-off distance (ds) to minimize the effect of MQL based plunge grinding on hardened AISI H13 tool steel in terms of lowest grinding force, specific energy, grinding temperature, and surface roughness using grey relational analysis. Taguchi’s L16 orthogonal array was utilized for conducting the final experiments and mist parameters varied through four levels include P (2, 3, 4, and 5 bar), Q (50, 100, 150, and 200 L/h) and ds (40, 50, 60, and 70 mm). Further, experimental analysis was carried out to compare the effect of optimal and worst mist parameters on ground surface and microchip by using microhardness, scanning electron microscope, and atomic force microscopy. According to validation test, P: 4 bar, Q:200 mL/h, and ds:50 mmare optimal mist parameters for multi-response variables of MQL grinding. Effective mist quality i.e. average droplet size of 51.03 μm was obtained at nozzle angle of 12°. Excellent ground surface quality with negligible microhardness variation and no wear tract microchip were observed under optimal mist setting.

Thermal damage restrict the capability of grinding in achieving the desired production rate; therefore, the present study focuses on the employment of a non-destructive Barkhausen noise (BN) technique in the assessment of thermal damages produced from grinding of hardened IS 2062 steel under dry (no lubrication) and wet (with lubrication) conditions. Optical microscopy along with microhardness measurement was utilized to reveal the microstructural and hardness alternation occurred in the ground and subsurface of sample. X- ray diffraction peak shift was measured and used for qualitative analysis of residual stress. Furthermore, surface topography was obtained by scanning electron microscope. The magnetic response from ground surface were measured in terms of Barkhausen noise (root mean square) and hysteresis loop (average permeability). The result shows very poor magnetic response from ground hardened steel due to higher carbon content. A non-linear variation is observed between peak shift and root mean square value of Barkhausen noise. However, average permeability derived from hysteresis loop shows good correlation with the peak shift with a correlation coefficient of approximately 0.8149.

Hysteresis loop analysis technique, being a non-destructive testing technique is more beneficial than the destructive testing techniques to characterise the welded plate. In this study, the ferritic stainless steel AISI 409L plate was butt welded by gas metal arc welding process. Hysteresis loop analysis technique was used to study the microstructures and microhardness of the base metal region, heat affected zone and weldmetal zone. This study has been carried out at four different values of magnetic field intensity 250, 500, 750 and 1000 Oe. The effect of variation of magnetic field intensity on the hysteresis loop characteristics (average maximum flux density and core loss) has been investigated for base metal, heat affected zone and weldmetal zone. It was found that for each region, the average maximum flux density as well as core loss increases on increasing magnetic field intensity. Also, the variation of average maximum flux density is inversely proportional to the microhardness of the region at each value of magnetic field intensity.

Characterisation of the welded plate by Non-destructive testing technique are gaining more popularity over destructive testing. In this study, the variation in the hysteresis loop behaviour were examined with the variation of magnetic field intensity on the base metal, heat affected zone and weld metal regions of gas metal arc welded ferritic stainless steel plate. The behaviour of hysteresis loop characteristics such as average permeability, remanence and coercivity have been investigated and it was found that these characteristics depend upon the grain size and microhardness as well as magnetic field intensity. Coercivity of each region vary in proportion with the variation of magnetic field intensity and inversely proportional to the grain size, but the variation of other hysteresis loop characteristics with the magnetic field intensity in each region is irregular.

Objective of current study is to analyse the effect of excitation frequency, magnetic field intensity and waveform on the hysteresis loop and Barkhausen Noise signals. As the property of ferromagnetic material especially the hysteresis loop and Barkhausen noise depends on microstructure, excitation frequency and magnetic field intensity. In this study the hysteresis loop and Barkhausen noise of the mild steel sample were experimentally measured by varying the frequency, intensity and waveform using magnetic Barkhausen noise analyser. Sinusoidal and triangular waveform were applied in varying frequency (0.1 Hz to 0.4 Hz) and intensity (250 Oe to 1000 Oe) for hysteresis loop whereas for Barkhausen noise analysis frequency varies from 20 Hz to 50 Hz and intensity varies from 250 Oe to 1000 Oe. Characteristics of hysteresis loop and magnetic Barkhausen noise depends upon magnetizing parameter and waveforms were explained with the help of micro magnetic theory.

Present work aims to increase the weld strength by combining Metal Inert Gas Welding (MIG) and Shielded Metal Arc Welding and reduce the dependence on inert gas used in MIG welding by relying on the flux of electrode to provide the shielding effect. It also aims to reduce the HAZ by reducing the melting of base metal, instead filling the grooves by molten mild steel electrode which is used in SMAW. Steel plates (IS-2062 grade) of 6mm thickness were welded in a single pass by placing a mild steel electrode (E6013) between them. The Shielding Gas used was CO2. Pre-weld preparations included making grooves with various included angles and Root gaps. Characterization was done using Optical Microscope. Micro-hardness test was carried out to confirm the above results. As flux of the electrode forms shielding gas and slag on the top of the weld, flow rate of the gas can be reduced to a much lower extent.

Although copper has its use in many industrial and functional applications, but its low wear resistance limits its potential application. Hard particulates are generally reinforced in bulk copper to increase its wear resistance but it tend to decrease its toughness. Thus the present research focuses on synthesis of copper based surface composite by friction stir processing. Zircon sand was used as reinforcement in copper as it is hard and fairly inexpensive. To prepare the composites, a groove of defined dimension was machined in the copper plate for compaction of zircon sand (18 vol%) at the centre of the plate. After filling the zircon sand in grooves, friction stir processing technique was employed to reinforce it in copper. For microstructure analysis, XRD, microhardness and wear characterization, specimens were cut from the processed portion of the plate. The micrograph obtained by optical and scanning electron microscope revealed equiaxed and fine grain structure in stir zone with no sign of concentration gradient, aggregation and segregation of particles. XRD pattern revealed no peaks corresponding to intermetallics or interfacial reaction products. The microhardness and wear resistance of fabricated surface composite improved significantly as compared to pure copper. The micrograph of worn surface was also analysed to investigate the predominant wear mechanisms. Adhesion and delamination wear were predominant wear mechanisms in pure copper whereas these wear mechanism was not significant in Cu/Zircon composite.

The SZ anisotropic work hardening behavior in duplex ferrite-martensite phase (DFM) microstructures has not been investigated yet. It is an important consideration for the selection of the stretch formability direction of the friction stir processed blank used for sheet metal forming applications. The anisotropic work hardening behavior is characterized by using miniature tensile specimens prepared along longitudinal (LD) and transverse (TD) directions. The tribological parameters such as coefficient of friction (COF) and wear rate at LE value of 6 are 0.57 and 0.5 × 10 − 10 m 3 / Nm . The effect of surface texture on the work hardening response is observed to be negligible. The plastic anisotropy in terms of three and multi-stage work hardening behaviors is investigated at a linear energy (LE) value of 6. The global true stress-strain responses and fracture surface morphologies suggested that the deformation occurs in different stages. In the initial stage, the deformation is mainly localized in the soft ferrite phase followed by the distinct work hardening stages in the plastic flow curves. In the elastic and elastoplastic region of the flow curve, the soft ferrite phase plastically deformed, followed by stress transfer to the martensite/retained austenite phases in the fully plastic region. The (110) and (111) pole figure suggested that the active in-habit-plane slip system is (110) and [ 1 1 ‾ 1 ] . The strain localizes more in the V19 + V22 block having the critical resolved shear stress (CRSS) value of 445.5 MPa. The retained austenite (RA) is having ( − 11 − 1 ) A / / ( 0 − 11 ) F and [ 011 ] A / / [ 111 ] F type Kurdjumov-Sachs (K–S) orientation relationship with the ferrite phase. A BCC {112} -type twinned laths is found to be present within the martensite laths. The recommended stretch formability direction (SFD) should coincide with the longitudinal or processing direction of the friction stir processed blank.

Material properties of IS 2062 steel plates after friction stir welding has been characterized by hysteresis loop characteristics at three different frequency range; low frequency, medium frequency and high frequency range. Magnetic field was applied with sinusoidal waveform and triangular waveform over base metal and friction stir welded sample for comparative analysis. Rectangular sample of 3 mm thickness were welded using tungsten carbide tool having 15 mm shoulder diameter at 800 RPM and 150 mm/min welding speed. Micro-hardness testing and metallographic study of welded samples were also performed to study the effect of change in material properties on magnetic response of material. Grain refinement upon friction stir welding changed the microhardness of weld nugget. Depth of penetration of external magnetic field at three different frequencies ranges not only changed the shape of hysteresis loop but also resulted into wide variation in hysteresis loop characteristics such as permeability, remanence, average maximum flux density and core loss.

The variation of heat input on microstructure and mechanical properties in gas metal arc welding of ferritic stainless steel (grade 409 L) using two different austenitic filler wires ER304 L and ER308 L have been discussed in this work. Three different heat input parameters of 0.3, 0.4 and 0.5 kJ mm−1 are used in this experimental work and the effect of heat input on the properties of weldment were investigated using metallographic study and mechanical testing. Percentage dilution, chromium nickel ratio, microstructure, microhardness and tensile properties were all found to be affected by the heat input. It was observed that welded sample with heat input of 0.4 kJ mm−1 possesses superior mechanical properties irrespective of type of filler wire used. Mechanical properties obtained by using 304 L filler wire were found to be better than those obtained using 308 L filler wire, irrespective of heat input provided during welding.

The research goal of present experimental work was to analyse the variation in magnetic response (at different magnetising frequency and magnetic field intensity) of IS-2062 steel of grade B upon friction stir welding (FSW). Tungsten carbide tool having 15 mm shoulder diameter was used to weld the steel plates having 3 mm thickness with welding speed of 150 mm per minute and revolving speed of 800 revolutions per minute. Welded steel plates were characterised using Barkhausen Noise analyser. Magnetic response of material, before welding and after welding was recorded in terms of Barkhausen Noise signal parameters that are root mean square (rms) value of signal and number of pulses. Both the signal parameters was observed to correlate well with grain refinement and changes in micro-hardness upon FSW of steel at different analysis parameters such as magnetic field intensity and excitation frequency.

The goal of present research work is to study the variation in the shape of hysteresis loop owing to change in the analysis parameter i.e., magnetising frequency and applied magnetic field strength upon pack carburised low carbon steel samples. Pack carburised heat treatment performed at three different temperatures to induce varying hardness into steel samples. Hysteresis loop characteristics such as coercivity, permeability, power loss and remanence were measured in a wide range of magnetising frequency and magnetic field intensity. Coercivity is observed to increase with increase in magnetising frequency and applied field strength. In low-frequency range ( 1 Hz) results into increase in remanence and power loss. However, with an increase in magnetic field strength both remanence and power loss were found to increase.