The Effects on Microstructure and Hardness of 0.28% Vanadium and 0.87% Nickel Alloyed Ductile Iron after Boronizing Process

2017 ◽  
Vol 740 ◽  
pp. 65-69 ◽  
Author(s):  
Khalissah Muhammad Yusof ◽  
Bulan Abdullah ◽  
Mohd Faizul Idham ◽  
Nor Hayati Saad
Keyword(s):  
Ductile Iron ◽  
Optical Microscope ◽  
Boride Layer ◽  
Holding Time ◽  
Material Surface ◽  
Micro Hardness ◽  
Surface Layers ◽  
Hardness Tester ◽  
Double Phase ◽  
Wear And Corrosion

Boronizing/boriding is a thermo mechanical process which produced protective surface layers to enhance the performance of engineering components utilized in mechanical, wear and corrosion. The present study investigate the microstructure and the hardness of boride layers formed on 0.28% Vanadium and 0.87% Nickel alloyed ductile iron after boronizing process. Specimens were boronized at 950° C for 6, 8 and 10 hours holding time before being cooled in the furnace. The microstructure and boride layer formed on the surface of substrates were observed under Olympus BX60 Optical Microscope. Vickers Micro Hardness Tester was also performed to determine the hardness of boride layers. Boride layer was formed by diffusion of the boron into the metal lattice at the surface which composed double phase of FeB and Fe2B with saw-tooth morphology. The results of this study indicated that the thickness of boride layers increased from 109.8μm at 6 hours to 195.4μm at 8 hours holding time before they crack at 10 hours. The hardness of the material surface also increased from 1535 HV to 1623 HV at 6 and 8 hours respectively. In conclusion, the microstructure, borides thickness and hardness of borides layer were depending on boronizing time while temperature kept constant.

The Effect of Surface Treatment on 0.16% Chromium and 1.32% Nickel Alloyed Ductile Iron (Di) through Boronizing Process

2017 ◽  
Vol 740 ◽  
pp. 70-74
Author(s):  
Khalissah Muhammad Yusof ◽  
Bulan Abdullah ◽  
Muhammad Haziq Samion ◽  
Mohd Faizul Idham ◽  
Nor Hayati Saad
Keyword(s):  
Ductile Iron ◽  
Wear Test ◽  
Optical Microscope ◽  
Boride Layer ◽  
High Wear Resistance ◽  
Wear Volume ◽  
Slurry Erosion ◽  
Hardness Tester ◽  
Before And After ◽  
Effect Of Surface

This paper aim to investigate the effect on microstructure, hardness and wear (slurry erosion) of alloyed ductile iron (DI) with addition of 0.16% Chromium and 1.32% Nickel before and after boronizing process. The specimens were prepared by melting the Ductile Iron compositions through CO2 sand casting method. Specimens were fully coated with boronizing paste and heated at 850°C and 900°C for 8 hours holding time. Microstructures of the specimens were observed under Olympus BX 41M Optical Microscope. Vickers Micro Hardness Tester was used to determine the hardness of the specimens while Wear Test (Slurry Erosion) to measure the wear volume of each specimen. After boronizing process, the boron element diffused into the specimens which make the surface harden. The thickest boride layer was detected at sample with temperature 900°C. The samples of 900°C give higher hardness than temperature 850°C which is 2909 HV and 1395 HV respectively. Referring to surface roughness test, samples boronized at 900oC had high wear resistance compared to sample boronized at 850oC and as cast. The selection temperature in boronizing treatment can prevent the rate of wear thus can identify the hardness of surface in order to prolong the equipment and application or even structure.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

scholarly journals Influence of the resistive-pulse welding parameters of nickel super-alloys on selected properties of the connection

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1060-1062
Author(s):  
Sławomir Spadło ◽  
Wojciech Depczyński ◽  
Piotr Młynarczyk ◽  
Tadeusz Gajewski ◽  
Jarosław Dąbrowa
Keyword(s):  
Optical Microscope ◽  
Mechanical Tests ◽  
Welding Parameters ◽  
Thin Sheets ◽  
Micro Hardness ◽  
Hastelloy X ◽  
Haynes 230 ◽  
Hardness Tester ◽  
Resistive Pulse ◽  
Pulse Welding

Microstructure and mechanical tests of welds of thin sheets made from nickel-based super-alloys (Haynes 230 and Hastelloy X) were presented. The welds were made using the resistive-pulse micro-welding method using the WS 7000S device. The micro-hardness of the joints was measured with a Matsuzawa Vickers MX 100 hardness tester at 100 G (0.98 N). Metallographic observations of the prepared micro-sections were performed using the Nikon Eclipse MA200 optical microscope at various magnifications. The metallographic microstructure studies were supplemented by linear analysis of the chemical composition, for which the OXFORD X-MAX electron microscope was applied.

Investigation on Recovery and Recrystallization of Al-Si-Al2O3 Composites

2013 ◽  
Vol 813 ◽  
pp. 345-350
Author(s):  
Xiong Wei Wang ◽  
Xiao Song Jiang ◽  
De Gui Zhu ◽  
Luo Zhang
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Optical Microscope ◽  
In Situ Synthesis ◽  
Recrystallization Temperature ◽  
Recrystallization Behavior ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Scanning Electron

Al-Si-Al2O3 composites were prepared by powder metallurgy with in-situ synthesis technology. The recovery and recrystallization behavior of Al-Si-Al2O3 composites which underwent compression and then heat-treatment under different temperature were studied using micro-hardness tester, optical microscope (OM) and scanning electron microscopy (SEM) . The results showed that the hardness of composites increased dramatically after compression, and the sample containing 5wt% Si was increasing more evidently than the sample including 10wt%Si. Heat treatment gradually eliminated work hardening; meanwhile the fact that the hardness of composites trended to decline greatly when subjected to annealing suggested occurrence of recovery and recrystallization inside the composites. Recrystallization nucleation preferentially took place in the region near the particle, while the growth of recrystallized grains can also be hindered owning to the pining effect of particles. Depending on the analysis of microstructure and microhardness, it can be concluded that the recrystallization temperature of Al-wt.5%Si-Al2O3 composites was 500°C and the Al-wt.10%Si-Al2O3 composites was 525°C.

Characterisation of WC-17Co and WC-9Ni HVOF Sprayed Cermet Coatings

2016 ◽  
Vol 840 ◽  
pp. 331-335
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi
Keyword(s):  
Steel Substrate ◽  
Optical Microscope ◽  
Binder Phase ◽  
High Porosity ◽  
Tungsten Carbides ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Vickers Micro Hardness

Cemented tungsten carbides have been paid much attention due its better mechanical properties with excellent combination of hardness and toughness characteristics. The hard WC particles in the coating provide hardness and wear resistance, while the ductile binder such as Co and Ni contribute to toughness and strength. WC-17wt.% Co and WC-9wt.% Ni powders have been sprayed by the HVOF method to form coatings approximately 300μm and 150μm thick onto AISI 1018 steel substrate. Both coatings have been prepared and supplied by an external vendor. The coatings were examined using optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The hardness of both coatings were also measured using Vickers micro-hardness tester. The microstructure of the coatings has been analyzed and found to consist of WC, brittle W2C phase, metallic W phase, and amorphous binder phase of Co and Ni. It is found that WC-Ni has a higher hardness value compared to WC-Co due to high porosity distribution.

ANALYSIS ON MICROSTRUCTURE, HARDNESS AND SURFACE ROUGHNESS OF SHOT BLASTED-PASTE BORONIZED 316 AUSTENITIC STAINLESS STEEL

2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Muhamad Hafizuddin Mohamad Basir ◽  
Bulan Abdullah ◽  
Siti Khadijah Alias ◽  
Muhammad Hafizuddin Jumadin ◽  
Muhammad Hussain Ismail
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Optical Microscope ◽  
Boride Layer ◽  
Surface Metrology ◽  
Boron Diffusion ◽  
Shot Blasting ◽  
Heavy Load ◽  
Hardness Tester

In this research, analysis on microstructure, hardness and surface roughness of 316 austenitic stainless steel were conducted before and after boronizing process. Boronizing treatment was conducted using a paste medium at a temperature of 8500C, with and without shot blasting. Microstructures of the specimens were observed under Olympus BX60 Optical Microscope. Vickers Micro Hardness Tester was used to determine the hardness of the specimens while Optical 3D Surface Metrology Sys was used to measure the surface roughness of the specimens. The process of boronizing diffuses boron into the surface of steel which resulted in the formation of the boride layers that consist of FeB and Fe2B. Shot blasting process increased the boron diffusion which resulted in increment of the boride layer thickness and hardness value while the surface roughness was fluctuated. Increment in the hardness value of 316 stainless steel causes the steel to be able to withstand a heavy load.

Application of Laser Additive Enhancing Technology in the Field of Cutting Tools

2017 ◽  
Vol 872 ◽  
pp. 8-13
Author(s):  
Yuan Ren ◽  
Wen Tao Wang ◽  
Xin Qiang Ma ◽  
Wei Cheng
Keyword(s):  
Grain Boundary ◽  
Cutting Tools ◽  
Alloy Coating ◽  
Optical Microscope ◽  
Solid State Laser ◽  
Micro Hardness ◽  
Hard Phase ◽  
Hardness Tester ◽  
Scanning Electron ◽  
Steel Cutting

Fe62 alloy coating was fabricated on the surface of #45 steel cutting edges with 2kW all-solid-state laser and powder feeding device. The substrate and forming layer are characterized by optical microscope and scanning electron microscope for microstructure, and tested by micro-hardness tester for micro-hardness. The results show that the forming layer combined with the substrate metallurgically. The microstructure of substrate is eutectoid ferrite and pearlite. The microstructure of layer is uniform and compact, with hard precipitation. The content of Cr, the hard phase generated element, at the grain boundary, is higher than that of grain inside and many hard phases were generated at the grain boundary. Compared with the substrate, the micro-hardness of forming layer increases by about 2 times. All these results show that application of laser additive enhancing technology in the field of cutting tools has larger potential.

scholarly journals Effect of Deep Cryogenic Treatment on Microstructure and Wear Resistance of LC3530 Fe-Based Laser Cladding Coating

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2400 ◽  
Author(s):  
Xiao Zhang ◽  
Yajun Zhou
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Room Temperature ◽  
Cryogenic Treatment ◽  
Optical Microscope ◽  
Material Surface ◽  
Wear Coefficient ◽  
Deep Cryogenic Treatment ◽  
Hardness Tester ◽  
Alloy Compound

The effect of deep cryogenic treatment on microstructure and wear resistance of LC3530 Fe-based powder laser cladding coating was investigated in this paper. The cladding coating was subjected to deep cryogenic treatment for the different holding times of 3, 6, 9, 12, and 24 h, followed by tempering at room temperature. Microstructure of the cladding coating was observed by optical microscope (OM) and the microhardness was measured by the Vickers-hardness tester. The wear was tested by ball and flat surface grinding testing conducted on the material surface comprehensive performance tester. The wear scars were analyzed using a non-contact optical surface profiler and scanning electron microscope (SEM). The results showed the grain size of cladding coating after 12 h of deep cryogenic treatment was significantly reduced by 36.50% compared to the non-cryogenically treated cladding coating, and the microhardness value increased by approximately 34%. According to the wear coefficient calculated by the Archard model, the wear resistance improved about five times and the wear mechanism was micro-ploughing. The deep cryogenic treatment could enhance the wear resistance of the cladding coating by forming a wear resistant alloy compound and higher surface microhardness.

The dependency of the microhardnes on microstructure and solidification parameters of directionally solidified Al–4.5wt.%Cu in clay mold

2020 ◽  
Vol 14 (3) ◽  
pp. 7125-7131
Author(s):  
Dedy Masnur ◽  
Viktor Malau ◽  
Suyitno Suyitno
Keyword(s):  
Solidification Process ◽  
Optical Microscope ◽  
Cooling Curve ◽  
Mold Material ◽  
Micro Hardness ◽  
Directionally Solidified ◽  
Steel Mold ◽  
Hardness Tester ◽  
Microstructure Parameters ◽  
Solidification Parameters

Improvement of material properties is achieved by controlling parameters involved in the solidification process; therefore, understanding them and their implication are essential. This work investigated the dependency of solidification parameters (cooling rate (TR), growth rate (VL), local solidification time (tSL), temperature gradient (G)), microstructure parameters (primary (λ1) and secondary (λ2) dendrite arm spacing), and micro-hardness values (HV) of Al-4.5wt.%Cu in the clay mold. The samples were directionally solidified in Bridgman vertical apparatus and the temperature is recorded during the cooling. The solidification parameters were obtained from the cooling curve. The microstructures and micro-hardness were characterized using an optical microscope and micro-hardness tester. The microstructure parameters were measured and plotted as functions of solidification parameters using linear regression. The relation between HV and microstructure parameters are analyzed. The results show the λ1 and λ2 change inversely with solidification parameters except for tSL. Comparison to other works shows the exponent values of solidification parameters of the clay mold are lower than that of the carbon and stainless-steel mold. The exponent value of λ2 in the clay mold is -0.183, close to the value in the graphite mold. The clay has the potential as mold material since it characteristic close to the graphite.

The Effect of Al2O3 Concentration on Properties of Ni-W-P-Al2O3 Electroless Composite Coating

2012 ◽  
Vol 468-471 ◽  
pp. 1163-1166 ◽  
Author(s):  
Wan Chang Sun
Keyword(s):  
Corrosion Resistance ◽  
Composite Coating ◽  
Potentiodynamic Polarization ◽  
Steel Substrate ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Plating Bath ◽  
Hardness Tester ◽  
Al2o3 Concentration ◽  
Plating Solution

Ni-W-P-Al2O3 electroless composite coating was successfully co-deposited on 45 steel substrate using electroless plating. Optical microscope (OM), micro-hardness tester and potentiodynamic polarization were used to analyze the morphology, micro-hardness and corrosion resistance of the composite coating. The effect of Al2O3 concentration in the plating solution on the micro-hardness and corrosion resistance of the composite coating was mainly discussed. The results show that Al2O3 particles co-deposit with Ni-W-P homogeneously. The micro-hardness and corrosion resistance of the coating are improved with the increasing of Al2O3 concentration in the plating bath, and then decrease at a high Al2O3 concentration.

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