Preheat Time Research Articles

A thermal modification technique combining bulk densification and heat treatment for poplar wood with low moisture content

This study aimed to obtain the most suitable process parameters of the bulk densification and heat treatment for the modification of poplar wood with a moisture content of approximately 3–5%. Based on the heat-mass transfer model, the best preheating temperature and time for the bulk densification process were 180 °C and 361 s, respectively. The optimal heat treatment temperature and time were 190 ℃ and 3 h, respectively. The resultant wood samples exhibited the highest storage modulus and the lowest loss factor, indicating that this kind of wood product has a long service life, suitable for solid wood flooring applications.

The influence of the long-term heating under H2 atmosphere on the tritium release behavior from the neutron-irradiated Li2TiO3

Solid tritium breeding materials are expected to be used in high-temperature conditions for a long time in a fusion DEMO reactor. Thus, it is important to understand how bred tritium releases from the long-term heated material under the environment as close to a DEMO condition as possible to establish a tritium fuel cycle and keep it safe. In this work, the tritium release behavior from the irradiated Li2TiO3 pebbles that was preheated for 720 h at most was observed by heating at 1000 °C under 1000 Pa H2/Ar gas flow. The release peaks of HTO and HT were observed around 300 °C due to the desorption of the chemisorbed water. Also, the broad HTO peak was observed in a higher temperature region despite purging H2/Ar gas. This result suggests that this tritium was released without exchanging with H2 but with combining with oxygen in the pebbles. Moreover, the released tritium amount decreased as the pre-heating time. Finally, the amount of tritium that could not be released by the heating experiment was quantified by dissolving samples with an acid solution. Besides, the total tritium release ratio was discussed.

Numerical Investigation of Successively Nucleating Bubbles During Subcooled Flow Boiling of FC-72 in Microgravity

For the present study numerical simulations of subcooled flow boiling of FC-72 in microgravity have been conducted to accompany boiling experiments performed in microgravity on the International Space Station (ISS). The numerical domain represents the geometry of the experimental test cell. For all simulations the open source framework OpenFOAM was employed, including extensions to the interFoam solver, which have been developed at the authors’ institute. A reference case has been defined applying intermediate values from the experimental parameter range as system parameters. This case has been examined thoroughly with regards to hydrodynamic phenomena and heat transfer during multiple, successive bubble cycles. Based on this reference case, the system parameters flow velocity, input heat flux, pre-heating time, and subcooling of the liquid bulk have been varied, and the impact of these quantities on bubble growth and movement as well as heat transfer have been studied. It was found, that an increased flow rate as well as increased subcooling lead to smaller bubbles and increased time between subsequent nucleations. A high input heat flux, an increased pre-heating time, and a decreased subcooling lead to a rapid cycle of bubble nucleation and coalescence.

OPTIMIZING THE TLD-100H READOUT SYSTEM UNDER VARIOUS RADIOACTIVE I-131 DOSES VIA THE REVISED TAGUCHI DYNAMIC QUALITY LOSS FUNCTION

The TLD-100H readout system performance under various radioactive I-131 exposure doses was optimized by four key factors via the revised Taguchi dynamic quality loss function. Taguchi dynamic analysis and the orthogonal array reorganizing the essential factors are crucial for the optimization of the thermoluminescent dosimeter (TLD) readout system given strict criteria of multiple irradiated environments and long-term exposure for calibrated TLDs. Accordingly, 96 TLD-100H chips were selected and randomly categorized into three batches with eight groups (four TLD chips in each group). Four factors, namely (1) initial temperature, (2) heating rate, (3) maximal temperature, and (4) TLD preheat time before reading were organized into eight combinations according to Taguchi suggestion, whereas each factor was preset at two levels. All 96 [Formula: see text] chips were put in three concentric circles with 30, 60, and 90 cm radii for 48 h, surrounding the radioactive 150[Formula: see text]mCi ([Formula: see text][Formula: see text]MBq) I-131 capsule and exposed to the cumulative doses of 88.2, 18.6, and 8.6[Formula: see text]mSv for the respective radii, accordingly. The TLD readings obtained from each group were analyzed to derive the sensitivity, coincidence, and reproducibility, then those were reorganized to draw four fish-bone-plots for the optimization. The optimal option for the TLD readout system implied the combination of A1 (a [Formula: see text]C initial temperature), B1 (a [Formula: see text]C/s heating rate), C1 (a [Formula: see text]C maximal temperature), and D2 (a 15[Formula: see text]s preheat time), which was further verified by the follow-up measurements. The dominant factors were A (initial temperature) and B (heating rate), whereas C (maximal temperature) and D (preheat time) were minor and provided negligible contributions to the system performance optimization.

The effect of chitosan form on the shape memory properties of polyurethane based composites

The continuous progress in the medicine and biotechnology demands development of novel biomaterials with multiple functions. This multifunctionality may be accomplished through combining synthetic polymers with shape memory properties and natural polymers. Shape memory composites consisting of poly(caprolactone-urethane) and chitosan (PU-2/3 PCL CH) were synthesized and evaluated in terms of structure–function correlation. Chitosan was incorporated in a form of microspheres (CH-Mic) or as the macromolecule unit (CH-m) of PCL-based polyurethane matrix (PU-2/3 PCL). The effect of chitosan on shape memory properties and transition temperature was evaluated. The PU-2/3 PCL CH-m composite demonstrated a lower transition temperature (Ttrans) of the shape recovery in comparison to neat PU-2/3 PCL matrix and PU-2/3 PCL CH-Mic composites. The composites with CH-m exhibited shape recovery immediately after reaching Ttrans whereas neat polymers and composites consisting of CH-Mic required five minutes pre-heating time before initialization of the shape recovery process.

Effect of pulsed electric current on electrically assisted indentation for surface texturing

Electrically assisted manufacturing has been widely studied for controlling material properties during the forming process and reducing flow stress and springback. In electrically assisted manufacturing, an electric current is applied during forming to improve the conventional forming process, and the type of electric current can be continuous or pulsed. Pulsed current has been widely applied today because of its high peak power and short processing time. In this study, the effects of pulsed electric current on electrically assisted indentation were examined on stainless steel 304, stainless steel 316, and titanium substrates. The electrically assisted indentation process consisted of a Vickers hardness tester, a power supply, and a controller. The effects of timing, amplitude, duty cycle, and frequency for electric current were examined. The experimental results showed that the timing of the electric current is important and there is an optimal preheating and total electric current time to achieve a large hardness reduction, which represents increased indentation depth and width at a constant load. The decrease in hardness clearly increased as the amplitude of the electric current increased. Finally, it was found that there is a close relationship between maximum temperature difference and hardness. This study provides guidelines for selecting process parameters in electrically assisted indentation using pulsed electric current for surface texturing.

Development of a methodology based on headspace-gas chromatography-ion mobility spectrometry for the rapid detection and determination of patin fish oil adulterated with palm oil

The present research intends to develop a new method based on headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) for the detection and determination of patin fish oil adulterated with different percentages of palm oil, because it is a cheaper vegetable oil. Five variables that affect headspace generation (incubation time and temperature, amount of sample, injection volume, and pre-heating time) have been optimized by means of a Box Behnken design in combination with Response Surface Methodology. Then, repeatability and intermediate precision have been studied where coefficients of variation lower than 10% were obtained. This new method has been applied to several samples of patin fish oil adulterated with palm oil at 20 different levels (5–50% palm oil content). The results have confirmed the suitability of the HS-GC-IMS for a rapid, easy, and reliable detection and discrimination of adulterated oil samples since a characteristic fingerprint that allows 100% successful discrimination between adulterated and unadulterated patin oil samples was achieved. Finally, a regression model has been developed to determine each sample’s adulteration level with an error lower than 10% and a coefficient of determination greater than 0.95.

Molecular dynamics simulation on evaporation of a suspending difluoromethane nanodroplet

Nanodroplet evaporation is a basic process widely existing in nature and industrial applications. Difluoromethane (CH2F2, also called “R32”) has attracted more and more attention in refrigeration, heat pump, Organic Rankine Cycle and other fields because of its excellent thermophysical characteristics. In this work, the evaporation process of R32 nanodroplet in large space is studied by means of molecular dynamics simulation. This work focuses on the dynamic evaporation characteristics of droplets under different conditions (droplet size, initial temperature, and ambient temperature) in the evaporation process, and quantitatively analyzes the effects of different parameters on the evaporation rate. The simulation results were compared with the results calculated from the diffusion-based model and the kinetic model. Based on the dynamic law of evaporation process, such as density, temperature field and velocity distribution, the calculation accuracy of each model is evaluated, the reasons for the deviation between model prediction and simulation results are also discussed. The results show that the increase of ambient temperature and initial saturation temperature can lead to a significant increase of droplet evaporation rate, and shorten the pre-heating time needed for droplet to reach quasi-steady evaporation stage. The increase of droplet size also increases pre-heating time, but has no significant effect on evaporation rate. For the evaporation scenario studied in this paper (Knudsen number (Kn) ~ 1), the existing modification methods of the kinetic model can enhance the prediction accuracy of the evaporation rate of R32 droplets in the quasi-steady evaporation stage. The prediction deviation of diffusion-based model applied directly is large, the accuracy of prediction can be significantly improved by correcting the thermal conductivity considering the scale effect.

Optimized simultaneous pressurized fluid extraction and in-cell clean-up, and analysis of polycyclic aromatic hydrocarbons (PAHs), and nitro-, carbonyl-, hydroxy -PAHs in solid particles

The development, modification and optimization of analytical methods capable of simultaneous extraction and in-cell clean-up of extracts for subsequent determination of parent PAHs and their associated transformed nitro-PAHs (NPAH), carbonyl-PAHs (CPAH) and hydroxy-PAHs (HO-PAH) products (TPPs) is essential for reducing the time and cost of analysis. The aim of this study was to modify and optimize the pressurized fluid extraction (PFE) technique capable of simultaneous extraction and in-cell clean-up of PAHs and TPPs in urban dust standard reference material and road dust for GC-MS analyses. In this study, multivariate data analysis such as factor analysis (FA), and preference ranking organisation method for enrichment evaluation (PROMETHEE) and geometrical analysis for interactive aid (GAIA) were used to assess the performance of the methods. As the key outcome of the study, an optimized selective reaction monitoring (SRM) Triple Quadrupole (TQ) electron ionization (EI)-GC/MS for measuring PAHs and TPPs without derivatization of polar HO-PAHs was developed. The limits of detection (LOD) for parent PAHs, CPAHs, NPAHs and HO-PAHs using Shimadzu TQ were 1.0–5.0 pg, 1.0–5.0 pg, 1.0–50.0 pg, and 1.0–25.0 pg, respectively. The PROMETHEE-GAIA analysis of the results showed that a combination of 3% deactivated silica gel and activated alumina (2:1) as in-cell clean-up material, and sequential PFE extraction (200 °C ASE temperature, 9 min preheat time and 3 times extraction cycle) using 100% hexane followed by hexane/DCM (1:1) is the best condition for analytes extraction from road dust. An optimized, fast and reliable GC/MS method operated solely in electron ionization (EI) mode was developed for measuring all analytes. The outcomes of this study will contribute significantly to future research on PAHs and TPPs, thereby promoting a safe and sustainable environment.

Pre-heating time and exposure duration: Effects on post-irradiation properties of a thermo-viscous resin-composite

ObjectiveTo evaluate the effects of pre-heating time and exposure duration on the degree of conversion (DC), maximum rate of polymerization (RPmax), polymerization shrinkage strain (PS) and surface micro-hardness (VHN) of Viscalor. MethodsViscalor syringes were pre-heated using a Caps Warmer (VOCO, Germany) in T3 mode (at 68°C) for 30s (T3-30s) and 3min (T3-3min) and then the composite paste was extruded into appropriately sized molds. Light irradiation was applied at zero distance from the upper surface with a LED-LCU of mean irradiance 1200mW/cm2 for either 20 or 40s. The real-time polymerization kinetics and DC at 5min and 24h post-irradiation (DC5min and DC24h) were measured using ATR-FTIR (n=3). PS was obtained with the bonded-disk technique (n=3). Top and bottom Vickers micro-hardness (VHNtop and VHNbottom) were measured at 5min post-irradiation and after 24h dry storage (n=5). Data were analysed using one-way ANOVA, two-way ANOVA, independent t-test and Tukey post hoc tests (p<0.05). ResultsPolymerization kinetic curves of Viscalor from 0 to 15min were similar for different pre-heating times and exposure durations. Pre-heated Viscalor (T3-30s and T3-3min) with 40s exposure had greater VHNtop and VHNbottom than for Viscalor (no heat) (p<0.05). Exposure duration did not significantly affect DC, RPmax and PS (p>0.05). After 24h storage, DC and VHN increased. Pre-heating did not increase the DC24h, relative to no pre-heating (p>0.05). Two-way ANOVA showed that there was no significant interaction between pre-heating time and exposure duration (p>0.05). SignificanceIncreasing irradiation time from 20 to 40s did not affect DC, RPmax or PS, but increased VHNtop. Composite pre-heating had no adverse effect through any premature polymerization. For Viscalor, 3min pre-heating and 20s irradiation were sufficient to provide adequate hardness, without increasing PS or compromising polymerization kinetics.

Novel method based on ion mobility spectroscopy for the quantification of adulterants in honeys

According to European Union Regulation, honey is a food product whose composition cannot be modified. However, high-quality honey is often adulterated by adding sweeteners of other sugar compounds. This paper studies the suitability of Ion Mobility Spectra from generated headspace as a method for the detection and discrimination of honey adulterated by different substances. A Box-Behnken design in conjunction with a response surface methodology was employed to optimize five different variables related to headspace generation (incubation temperature, incubation time, injection volume, weight of the samples and pre-heating time). The resulting model showed a regression coefficient of R2 = 88.07%, it is therefore suitable for a reliable selection of the experimental variables. Repeatability and intermediate precision were also evaluated, and coefficients of variation below 5% were obtained (CV of 4.6% and 4.2% respectively). The developed method has been applied to different samples resulting for the mixture of honey and other sweeteners at different percentages (5%–50%) in an attempt to mimic the adulterated products that are more commonly found in the market. A thorough and exact classification (100%) with regards to the presence/absence of adulterant as well as the type of adulterant used has been achieved. A Partial Least Squares regression model was completed in order to determine the percentage of the different adulterants. The prediction error was below 4% in all the cases. These results demonstrate the applicability of the developed method for the detection and quantification of adulterated honey with different adulterant contents.

Effect of Oil Oxidation on Acrylamide Formation in Oil-Rich Model Systems Without the Participation of Reducing Sugars

Oil oxidation in an oil-rich system was used to investigate the effect on acrylamide formation. Three kinds of common oil, soybean oil, olive oil, and palm oil, were preheated at different temperatures (120, 150, 180, and 210°C) for different times (0, 5, 10, 15, and 20 h). The oil-rich model systems were composed of pretreated oil and asparagine. Acid value, peroxide value, p-anisidine value, and carbonyl group value were used to monitor the degree of lipid oxidation in the model system. Our results showed that the content of acrylamide increased with oil preheat time and temperature. The highest yield of acrylamide in soybean oil was 0.26 ± 0.012 μg/mL after 20 h of incubation at 210°C. Oil oxidation indices correlated significantly with the content of acrylamide. The peroxide value could provide more information for references about acrylamide formation in soybean and olive oil systems.

Optimization of Investment Casting Parameters to Improve the Mechanical Properties by Taguchi Method

Investment casting is the most adaptable and durable manufacturing process dating back thousands of years, with a rapidly increasing application. It is used primarily for the development of complex components near net-shape. A wax pattern in the exact replica of the cast part is used here. When the mold has been formed, the wax pattern is melted out. For this purpose this process is called lost wax process. In this present study investment casting process parameter is optimized by using Taguchi approach to improve the mechanical properties of mild steel. A set of experiments were conducted as per Taguchi’s L9 orthogonal array to determine the most influential control factors. For test the performance characteristics, orthogonal range, signal to noise ratio and variance analysis were used. Data values are obtained under the constraint of different process parameters like preheat temperature, pouring temperature, preheat time to investigate their effects on the surface hardness, tensile strength of the final results. The variations in the trend of the mechanical properties were observed. It was found that high mold preheat temperature, higher pouring temperature, maximum preheat time significantly reduce the mechanical properties of the castings.

Joining of aluminium alloy to pre-holed carbon steel by aluminium extrusion using friction spot method

Purpose The purpose of this paper is to join sheets of an aluminium alloy together with pre-holed carbon steel via friction spot technique. Design/methodology/approach An AISI 1006 steel sheet was a pre-holed with a 4.8 mm diameter and put under AA5052 sheet with a lap joint configuration. The joining process was carried out by extruding the aluminium through the steel hole using a rotating tool of 10 mm diameter. Furthermore, three process parameters (pre-heating time, rotating speed and plunging depth of the tool) with three values for each parameter were used to study their effects on the joints quality. In order to join samples, nine experiments were designed according to a Taguchi method. Shear strength, microstructure and X-ray diffraction tests of the joint were carried out. Findings The joining mechanism occurred by a mechanical interlock of the extruded aluminium with the inner surface of the steel hole. The tool plunging depth had a significant effect on the shear strength of the joint. The shear strength of two joints exceeded the shear strength of the wrought material (AA5052). All samples failed with two modes: pull-out and shearing of the extruded aluminium. Originality/value For the first time, the extrusion technique was used to join AA5052 sheet together with pre-holed carbon steel, with a perfect joint efficiency.

Influence of a Zn Interlayer on the Interfacial Microstructures and Mechanical Properties of Arc-Sprayed Al/AZ91D Bimetals Manufactured by the Solid-Liquid Compound Casting Process.

A novel technique combining solid–liquid compound casting (SLCC) with arc spraying was designed to manufacture the arc-sprayed Al/AZ91D bimetals with a Zn interlayer. The Al/Mg bimetal was produced by pouring the AZ91D melt into the molds sprayed with Al/Zn double-deck coating, during which the arc-sprayed Zn coating acted as the interlayer. The effect of the Zn interlayer on microstructures, properties, and fracture behaviors of arc-sprayed Al/AZ91D bimetals by SLCC was investigated and discussed in this study. The optimal process parameter was acquired by analyzing the results from different combinations between the arc-spraying time of the Zn coating (10, 18, and 30 s) and the preheat time of the Al/Zn double-deck coating (6 and 12 h). The interfacial microstructures of the arc-sprayed Al/AZ91D bimetals with a Zn interlayer could be approximately divided into two categories: One was mainly composed of (α-Mg + Al5Mg11Zn4) and (α-Al + Mg32(Al, Zn)49) structures, and the other primarily consisted of (α-Mg + Al5Mg11Zn4), (MgZn2 (main) + β-Zn), and (β-Zn (main) + MgZn2) structures. In the interface zone, the (α-Mg + Al5Mg11Zn4) structure was the most abundant structure, and the MgZn2 intermetallic compound had the highest microhardness of 327 HV. When the arc-spraying time of the Zn coating was 30 s and the preheat time of the Al/Zn double-deck coating was 6 h, the shear strength of the arc-sprayed Al/AZ91D bimetal reached 31.73 MPa. Most rupture of the arc-sprayed Al/AZ91D bimetals with a Zn interlayer occurred at the (α-Mg + Al5Mg11Zn4) structure and presented some typical features of brittle fracture.

Pre-heating effects on extrusion force, stickiness and packability of resin-based composite

ObjectivesTo measure temperature effects on stickiness and packability of representative resin-based composites and the effect of pre-heating time on pre-cure properties of Viscalor, including extrusion force. MethodsFive resin-based composites (RBC) and an additional RBC, Viscalor, used with a Caps Warmer (VOCO, Germany) were studied. The extrusion force (N) and extruded mass (g) were measured from Viscalor compules heated in T3 mode for 30s (T3-30s) and 3min (T3-3min). For stickiness and packability measurements, RBCs were packed into a brass cylindrical cavity controlled at 22 and 37°C. A flat-ended probe was lowered into the RBC pastes at constant speed. Stickiness: Fmax (N) and Ws (N mm), and packability: Fp (N), were measured. Viscalor was LED photo-cured at 1200mW/cm2 for 40s. The degrees of conversion at 5min and 24h post cure (DC5min and DC24h) of Viscalor (no heat, T3-30s and T3-3min) were measured by ATR-FTIR. Data were analysed by one-way ANOVA, independent t-test and Tukey post-hoc tests (p<0.05). ResultsThe maximum temperature of the Caps Warmer, in T3 mode, reached 68°C in 20min. Viscalor temperatures of 34.5°C and 60.6°C were recorded after 30s and 3min pre-heating, respectively. Pre-heating significantly reduced extrusion force and increased extruded mass, especially after 3min. RBCs varied in Fmax, Ws and Fp (p<0.05). Temperature also affected Fmax (p=0.000), Ws (p=0.002) and Fp (p=0.000). Pre-heating Viscalor for either 30s or 3min did not increase the post-cure DC at either 5min or 24h, relative to no pre-heating (p>0.05). SignificanceThe composites varied to an extent in stickiness and packability but the overall magnitudes remained within a clinically acceptable range. Pre-heating was beneficial in placement of Viscalor and caused no adverse effects through premature polymerization.

Optically stimulated luminescence of Dy3+-doped NaCaPO4 glass-ceramics

Dy3+-doped glass-ceramics containing NaCaPO4 crystals were successfully fabricated by heat treatment at base glass, and the luminescence properties were investigated for potential applications in radiation measurements. The photoluminescence (PL) excitation and emission spectra exhibit transitions related to Dy3+ ions corresponding to the strongest excitation and emission wavelengths at 351 and 575 nm, respectively. The CW-OSL properties as a function of dopant concentration, pre-heating temperature, pre-heating time and signal fading were investigated. The most appropriate Dy3+ ion concentration was found to be 0.25 mol%. The TL glow curves have a broad peak feature peaking at 195 ± 5 °C. The fading of the OSL signal would keep stable in five days with the intensity value of about 76.11%. The samples also exhibit good signal reusability and a broad linear dose response range (0.02–1000 Gy).

Resistojet thruster with supercapacitor power source – design and experimental research

The paper presents the design of and experimental research on a resistojet thruster with a dedicated power supply system based on supercapacitors. First, the description of two research stands used in different stages of the research is presented. The experimental approach divides the research into two phases. The first part focuses on optimization of the heating chamber, which has a laboratory power supply as a power source. Seven configurations of the chamber – differing in the number of coaxial channels and spiral heaters – are presented together with the results of the optimization process. The second stage describes research into thruster-like conditions with both power supply systems – supercapacitor based and with a laboratory power supply – with the geometry chosen based on the optimization process. A comparison is presented of propulsion parameters for various pre-heating times, power levels and power supply types, with a cold gas system as a reference.

Characterization of the thermally transferred optically stimulated luminescence (TT-OSL) of BeO

The objective of this work was to characterize more in depth the newly discovered thermally transferred optically stimulated luminescence (TT-OSL) of BeO. The studies include a more detailed investigation of the pre-heating temperature and time required to induce the TT-OSL signal; the reproducibility, additivity, and stability of the TT-OSL signal at room temperature and under ambient light exposure; the TT-OSL response to high doses (up to 25 Gy); and the possible recuperation of the OSL signal at room temperature. The results indicate that the TT-OSL is maximum for a pre-heating to 260 °C, if a heating rate of 5 °C/s is used. The TT-OSL decreases with readouts (pre-heating plus OSL readout), indicating depletion of the source of trapped charges. Sensitivity changes are observed in both OSL and TT-OSL signals to the same extend. Furthermore, it was demonstrated that the TT-OSL is additive: the TT-OSL is proportional to the total dose delivered to the detector, whereas the OSL signal is proportional to the dose since the last bleaching. This relationship holds up to ∼5 Gy; above this dose, the TT-OSL starts to saturate. The kinetics of the TT-OSL signal with pre-heating temperature and duration is consistent with a simplified model in which charges from an optically insensitive (or “difficult to bleach”) trap are transferred to an optically sensitive trap, both having similar thermal stabilities with a difference in activation energy of the order of 0.1 eV. The TT-OSL signal is stable in the dark up to the maximum duration investigated here (50 days), decaying slowly under exposure to ambient light. Furthermore, we report evidence of recuperation of the OSL signal at room temperature, which may be caused by a similar process as the one responsible for the TT-OSL signal. The results have obvious implications for practical dosimetry using BeO, including the possibility of re-estimating the doses if the detectors are accidently exposed to light, the possibility to check if the detectors have been exposed to light, the potential recuperation of OSL signal at room temperature and its influence on dosimetry if the detectors have been exposed to high doses, or the potential to use the shape of the OSL curve or the ratio between the OSL and TT-OSL signals for linear energy transfer estimation in ion beam dosimetry.

Fabrication of dissimilar Fe-Cu-C powder metallurgy compact/steel joint using the optimized resistance spot welding

The main parameters of resistance spot welding were optimized using Taguchi method for dissimilar joining of low carbon steel and Fe-Cu-C powder metallurgy compact. In order of importance, preheat current, preheat time, hold time, welding current and welding time affect the strength of weld. Different constituents such as lath martensite, ferrite, pearlite and carbide colonies were observed in the microstructure of welds. The maximum hardness and strength of joints was 735 HV and 5.75 kN, respectively. The presence of hard zone in the fusion zone improved strength values and encouraged the pullout failure mode. The width of hard zone was increased by application of high preheat current and low welding current.