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

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.

2017 ◽  
Vol 740 ◽  
pp. 65-69 ◽  
Author(s):  
Khalissah Muhammad Yusof ◽  
Bulan Abdullah ◽  
Mohd Faizul Idham ◽  
Nor Hayati Saad

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.


2021 ◽  
Vol 95 ◽  
pp. 18-23
Author(s):  
Minh Nguyen Ngoc ◽  

High Cr white cast iron is an alloy widely used in the field of manufacturing parts working in conditions of high wear resistance. However, the machining process for this alloy is often difficult due to its high hardness. Therefore, the objective of this study is to find out the appropriate parameters of heat treatment process to be able for softening of high Cr white cast iron with a lower hardness, ensuring the cutting process. In this study, the samples were austenitized partially and soft annealed in a resistance furnace. Optical microscope, X-ray diffractometer and field emission scanning electron microscope were used to observe and evaluate the microstructure of samples before and after heat treatment. The Rockwell hardness tester (RHT) is also used to evaluate hardness variation of samples. Research results have shown that the change of primary carbide grain size and formation of secondary carbides during heat treatment can reduce the hardness of white cast iron to the suitable range for machining.


2018 ◽  
Vol 188 ◽  
pp. 02007
Author(s):  
Enbiya Türedi

There are plenty of methods for determining the wear volume after a wear test. Due to the geometrical assumptions, some of them could unfortunately lead to mistaken results. It has been shown that a novel method, the direct microscopic measurement, is able to calculate the wear volume on a specimen surface very precisely and accurately [1-2]. It is based on creating a series of line profiles perpendicular to the wear scar. This novel method, however, needs to be characterized in terms of measurement limitations and minimum detectable volume capability. For example, how small or how shallow a wear scar could be calculated or measured with this method, must be determined. For this purpose, it has been prepared a series of wear test specimens exposed to the different amounts of wear in a “pin-on-disk” type test rig. As specimens, two different non-ferrous mold materials, Al bronze alloys, were selected and prepared metallographically. Counterpart materials were inox steel and bearing steel balls with diameter of 6 mm. Normal load was set to 5 N. Test configurations were set to 1, 5, 10 and 100 m of sliding distance values, in turn. Wear tests were conducted in according to ASTM G99 standard. Wear volume results were determined both direct microscopic measurement and also a 3D optical microscope methods. Comparison results showed that the novel method could be successfully used for wear volume calculations even with small amounts of wear volume conditions.


2013 ◽  
Vol 467 ◽  
pp. 122-126 ◽  
Author(s):  
T. Saravana Kannan ◽  
C. Piraiarasi ◽  
Abu Saleh Ahmed ◽  
Ani Farid Nasir

The present study aims to investigate the corrosion characteristics of copper commonly encountered in the spark ignition (SI) engine fuel system with Malaysian bioethanol and gasoline blends. Static immersion tests in E0 (gasoline), E10 and E85 were carried out at room temperature for 1320 h. Mechanical, physical and chemical properties of copper was investigated before and after immersion tests. Investigations were carried out on change in morphological properties using optical microscope; change in chemical structure using FTIR; change in mass and volume by weight loss measurement; hardness changes using universal hardness tester; and change of chemical properties of the fuel blends using total acid number titration method. The test results showed that corrosion of copper was increased with the high concentration of ethanol in the blends.


2015 ◽  
Vol 76 (3) ◽  
Author(s):  
Muhamad Hafizuddin Mohamad Basir ◽  
Bulan Abdullah ◽  
Siti Khadijah Alias ◽  
Muhammad Hafizuddin Jumadin ◽  
Muhammad Hussain Ismail

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.


2015 ◽  
Vol 137 (3) ◽  
Author(s):  
C. Liang ◽  
T. F. Su ◽  
Y. B. Wang ◽  
X. Han ◽  
M. L. Yin ◽  
...  

Wear behavior of Mg–5Al–0.8Zn alloy was studied using a pin-on-disk type wear apparatus within a load range of 20–380 N and a sliding speed range of 0.1–4.0 m/s. Analyzes on morphology and chemical composition of worn surfaces were undertaken using scanning electron microscope (SEM), energy dispersive X-ray spectrometer (EDS) for determination type of wear mechanism. Investigations on microstructure, plastic strain, and hardness in subsurfaces were carried out using optical microscope and hardness tester for understanding changes in the microstructure and hardness before and after mild to severe wear transition. The subsurface microstructure beneath the worn surface was subjected to a large plastic strain, and experienced strain hardening, dynamic recrystallization (DRX), and melting successively with increasing load or sliding speed. The transition between mild and severe wear was controlled by microstructure transformation from a strain-hardened into a thermal soften DRX microstructure in subsurface. A contact surface DRX temperature criterion is proposed for prediction of transition between mild and severe wear in Mg–5Al–0.8Zn alloy. The mild to severe wear transition loads were predicted under various sliding speeds using DRX kinetics. The validity of the proposed method for prediction of transition between mild and severe wear is also verified in AZ31 and AZ61 alloys.


Lubricants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Hamidreza Ghandvar ◽  
Mostafa Abbas Jabbar ◽  
Abdollah Bahador ◽  
Tuty Asma Abu Bakar ◽  
Nor Akmal Fadil ◽  
...  

In current study; the effect of various Gadolinium (Gd) additions on the microstructure and sliding wear behaviour of Al-15%Mg2Si composite before and after the hot extrusion process was examined. Optical microscopy (OM), scanning electron microscopy (SEM) equipped with EDX facility and X-ray diffraction (XRD) were used to characterize the microstructure. The results showed that with addition of 1.0 wt.% Gd to Al-15%Mg2Si composite, the primary Mg2Si particles size reduced from 44 µm to 23 µm and its morphology altered from dendritic to polygonal shape. Further refinement of primary Mg2Si particles was achieved after conducting hot extrusion which resulted in a decrease in its size to 19 µm with a transfer to near-spherical morphology. The Vickers hardness value increased from 55.6 HV in the as-cast and unmodified composite to 72.9 HV in the extruded 1.0% Gd modified composite. The wear test results revealed that composites treated with Gd possess higher wear resistance in comparison with those of without Gd. The highest wear resistance obtained with the lowest wear rates of 0.19 mm3/km and 0.14 mm3/km in the Al-15%Mg2Si-1.0% Gd before and after the hot extrusion, respectively. The high wear resistance of extruded Gd-modified Al-15%Mg2Si composite is due to the refinement of primary Mg2Si particles with uniform distribution in the composite matrix along with fragmentation of Gd intermetallic compounds.


2020 ◽  
Vol 4 (141) ◽  
pp. 157-163
Author(s):  
IL’YA ROMANOV ◽  
◽  
ROMAN ZADOROZHNIY

When applying coatings using various methods on the surfaces of moving parts that work in joints, it is important to make sure that the coatings are strong and wear-resistant in order to return them to their original resource. All existing hardening technologies and materials used to perform coatings have their own characteristics, therefore, the quality of the resulting coatings can be judged only after specific tests. (Research purpose) The research purpose is in evaluating the properties of the coating obtained by the method of electric spark hardening, and its ability to resist friction and mechanical wear. (Materials and methods) Authors conducted tests on the basis of the "Nano-Center" center for collective use. A coating was applied on the BIG-4M unit with a VK-8 hard alloy electrode, tribological properties were evaluated on a CSM Instruments TRB-S-DE-0000 tribometer, the width of the friction track was measured after the test using an inverted OLYMPUS gx51 optical microscope, and samples were weighed before and after the test on a VLR-200 analytical balance. Conducted research in accordance with GOST 23.224-86 and RD 50-662-88 guidelines. (Results and discussion) The article presents performed tests on the run-in and wear resistance of the coating. The samples were worked on with a step-by-step increase in the load. During the tests, the friction force was drawed on the diagram. Authors compared the results with the reference sample, an uncoated surface. (Conclusions) The resulting coating has better run-in and wear resistance compared to the standard, and the increase in wear resistance in dry friction conditions is very significant.


2015 ◽  
Vol 773-774 ◽  
pp. 168-172
Author(s):  
D. Harun ◽  
D. Nalatambi ◽  
Ramdziah Md. Nasir ◽  
Abdul Latif Mohd Tobi

Reciprocating sliding wear test of uncoated titanium alloy, Ti-6Al-4V is investigated using pin-on-flat contact arrangement of Ti-6Al-4V/Ti-6Al-4V pair under variable number of cycles at low number of cycles. The worn surfaces of the titanium alloy specimens were analyzed with the use of optical microscope (2D and 3D OM) and Vickers Hardness analysis was carried on. The pattern of the wear scar characteristics determined and the finding at the end of wear track had been focus through the presence at the end of wear track. It is suggesting an evidence of plastic deformation with the increasing in hardness value. The increase in hardness value at the end of wear track indicates increase in the plastic deformation with increasing number of cycles.


2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.


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