Multi-Objective Optimization of Process Parameters in Pack Siliconizing on AISI D2 Steel

Ghasempour-Mouziraji

Sadeghi

et al. 2021

Metall Mater Trans A

Self Cite

Silicon nitride (Si3N4) coating was deposited on AISI D2 tool steel through employing duplex surface treatments—pack siliconizing followed by plasma nitriding. Pack cementation was performed at 650 °C, 800 °C, and 950 °C for 2 and 3 hours by using various mixtures to realize the silicon coating. X-ray diffraction analyses and scanning electron microscopy observations were employed for demonstrating the optimal process conditions leading to high coating adhesion, uniform thickness, and composition. The optimized conditions belonging to siliconizing were employed to produce samples to be further processed via plasma nitriding. This treatment was performed with a gas mixture of 75 pct H2-25 pct N2, at the temperature of 550 °C for 7 hours. The results showed that different nitride phases such as Si3N4-β, Si3N4-γ, Fe4N, and Fe3N can be recognized as coatings reinforcements. It was demonstrated that the described composite coating procedure allowed to obtain a remarkable increase in hardness (80 pct higher with respect to the substrate) and wear resistance (30 pct decrease of weight loss) of the tool steel.

Section: Siliconizing Coatingsupporting

confidence: 54%

Characterization of Tribological and Mechanical Properties of the Si3N4 Coating Fabricated by Duplex Surface Treatment of Pack Siliconizing and Plasma Nitriding on AISI D2 Tool Steel

Ghasempour-Mouziraji

Sadeghi

et al. 2021

Metall Mater Trans A

Self Cite

“…Figure 5 shows the effect of the process parameters on the hardness of the coating. Three specific parameters have effect on the hardness of the coating: (i) treatment temperature, (ii) treatment time, and (iii) halide activator percentage used in the powder composition [17]. As the halide activator percentage increases, the silicon reactions kinetics improve.…”

Section: Effect Of Process Parameters On the Hardnessmentioning

confidence: 99%

“…So, the main goal of pack siliconizing optimization is the reduction of treating time and temperature by retaining acceptable levels of surface hardness and hardening compounds penetration. For this reason, the optimization of processing parameters is fundamental for the development of pack cementation in general and siliconizing in particular [12][13][14][15][16][17]. The main aim of the present paper is the obtaining of the best combination of processing parameters basing on experimental results and running values.…”

Section: Introductionmentioning

confidence: 99%

Pack Siliconizing Optimization of AISI D2 Tool Steel

Hosseinzadeh

Ghasempour-Mouziraji

et al. 2022

Silicon

Self Cite

The paper describes the pack siliconizing optimization procedure for AISI D2 tool steel. Pack siliconizing was performed by employing different treating temperatures (falling in the range 650–950 °C) and times (falling in the range 2–4 h). The siliconizing atmosphere was obtained through silicon (at 12 wt.%) with the addition of different percentages of NH4Cl (falling in the range 0.5–1 wt.%), Al2O3 was used as halide activator. The coatings’ phases evolution was analyzed through X-ray diffraction; the coatings’ thickness was measured through scanning electron microscopy observations of the cross section of the samples; the mechanical properties were evaluated through micro hardness measurements. The results showed that the coatings’ thickness and hardness increase as the treating time and temperature as well as the halide activator percentage increase. The coating procedure optimization was performed by employing the response surface methodology based on Box-Behnken method. The results of the optimization procedure led to the of the optimal combination of processing parameters: 1 wt.% of halide activator, 3.575 holding time, 950 °C in temperature.

“…Besides what has been mentioned, various researches have been done in the direction of the optimization of the production process. Najafizade et al [21] optimized siliconizing performance by using RSM method and experimental tests. Hoseinzade et al [22] optimized the tube drawing performance with rectangular tubes to optimize the friction coefficient, drawing velocity, bearing length and die half angle.…”

Section: Introductionmentioning

confidence: 99%

Optimization of biocorrosion resistance and mechanical properties of PM Ti–XAl–2Fe–3Cu alloys by response surface methodology

Ghasempour-Mouziraji²,

Hosseinzadeh³

et al. 2022

J Mater Sci

In the current study, the biocorrosion resistance and mechanical properties of the Ti–XAl–2Fe–3Cu (wt%) (X = 6, 4, 2 wt%) alloy produced by powder compact extrusion of blended elemental powders were optimized by using the response surface methodology in order to gain the best combination of processing parameters. To run the optimization process, central composite design with three equal levels of oxygen, hydrogen and aluminum was used and, by employing ANOVA, the analysis of variance was implemented. The results showed that the content of aluminum has a significant effect on the microstructure, mechanical properties, biocorrosion resistance and fracture behavior of the extruded rods. The highest aluminum content corresponds to the highest alloy strength and biocorrosion resistance. This was due to the reduction of the lamella thickness and of the material colonies as the aluminum content increases. Also, by running the experimental and optimization tests, the mechanical properties resulted 1245 MPa in yield strength and 1340 MPa in ultimate tensile strength with 0.1 µAcm−2 in corrosion current.