C.S. Chew, R. Durairaj, A. S. M. A. Haseeb and B. Beake
The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation…
Abstract
Purpose
The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation. It has been found that a ternary amorphous Sn-Ni-W layer formed below Ni3Sn4 IMC at the interface. In this study, mechanical properties of the IMC formed between SA solder and Ni-18 at. % W film after six times reflows were performed by nanoindentation.
Design/methodology/approach
The characterization was carried at 25°C, and 100 indents were generated. The elastic modulus and hardness were investigated.
Findings
The results showed that hardness of Ni3Sn4 IMC was higher than amorphous Sn-Ni-W phase. A slight bigger indent was observed on the Sn-Ni-W layer compared with that on the Ni3Sn4 IMC. Lower topographical height in the Sn-Ni-W layer indicated that the Sn-Ni-W phase was softer compared with the Ni3Sn4 IMC. The lower hardness and soft Sn-Ni-W phase is significantly related to the amorphous structure that formed through solid-state amorphization.
Originality/value
There are no publications about the indentation on the interfacial between the Ni-W layer and the Sn-Ag solder.
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Q.M Mehran, A.R Bushroa, M.A Fazal and M.M. Quazi
– The purpose of this study is to design and develop a new functional coating system for aerospace AL7075-T6 alloy that would evaluate the mechanical properties of the coating.
Abstract
Purpose
The purpose of this study is to design and develop a new functional coating system for aerospace AL7075-T6 alloy that would evaluate the mechanical properties of the coating.
Design/methodology/approach
This paper outlines the scratch adhesion characterisation of Cr/CrAlN coating using a combination of radio frequency (RF) and direct current (DC) physical vapour deposition (PVD) magnetron sputtering. The surface morphology, microstructure and chemical composition of the Cr/CrAlN film were evaluated by optical microscopy (OM), field emission scanning electron microscopy (FESEM) integrated with energy-dispersive X-Ray spectroscopy (EDX) and atomic force microscopy (AFM). The film-to-substrate adhesion was measured by a scratch test machine manufactured with a detection system, motorized stages, penetration depth sensors, optical microscope and tangential frictional load sensors.
Findings
The AFM and ultra-micro hardness results showed an increase in surface roughness to about 20 per cent and hardness to about 74 per cent. Moreover, the film-to-substrate adhesion strength of 1,814 mN was obtained with PVD deposition process.
Research limitations/implications
The main limitation of this work is caused by PVD deposition process. Besides, surface defects such as pinholes contribute to a decrease in adhesion strength.
Practical implications
The higher hardness of CrAlN coating is used to improve the properties of softer aluminium substrates. This hardness prevents ploughing-induced wear and provides greater adhesion strength by preventing coating delamination.
Originality/value
Until now, CrAlN is coated only on ferrous alloys. It has not yet been tried on aluminium alloys. Moreover, coating functionality depends on higher adhesion and failure mechanisms involved in the film-to-substrate system, which is significant in aerospace applications.
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Ahsana Aqilah Ahmad, Jaharah A. Ghani and Che Hassan Che Haron
The purpose of this paper is to study the cutting performance of high-speed regime end milling of AISI 4340 by investigating the tool life and wear mechanism of steel using the…
Abstract
Purpose
The purpose of this paper is to study the cutting performance of high-speed regime end milling of AISI 4340 by investigating the tool life and wear mechanism of steel using the minimum quantity lubrication (MQL) technique to deliver the cutting fluid.
Design/methodology/approach
The experiments were designed using Taguchi L9 orthogonal array with the parameters chosen: cutting speed (between 300 and 400 m/min), feed rate (between 0.15 and 0.3 mm/tooth), axial depth of cut (between 0.5 and 0.7 mm) and radial depth of cut (between 0.3 and 0.7 mm). Toolmaker microscope, optical microscope and Hitachi SU3500 Variable Pressure Scanning Electron Microscope used to measure tool wear progression and wear mechanism.
Findings
Cutting speed 65.36%, radial depth of cut 24.06% and feed rate 6.28% are the cutting parameters that contribute the most to the rate of tool life. The study of the tool wear mechanism revealed that the oxide layer was observed during lower and high cutting speeds. The former provides a cushion of the protective layer while later reduce the surface hardness of the coated tool
Originality/value
A high-speed regime is usually carried out in dry conditions which can shorten the tool life and accelerate the tool wear. Thus, this research is important as it investigates how the use of MQL and cutting parameters can prolong the usage of tool life and at the same time to achieve a sustainable manufacturing process.
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Hongjin Zhao, Lei Cao, Yong Wan, Shuyan Yang, Jianguo Gao and Jibin Pu
The purpose of this paper is to increase wear resistance of aluminum.
Abstract
Purpose
The purpose of this paper is to increase wear resistance of aluminum.
Design/methodology/approach
The authors have studied the ways to improve the tribological performance of aluminum by assembling stearic acid on aluminum coated by sol-gel-derived TiO2 film. The samples were characterized by infrared spectroscopy, contact angle measurements and a macro friction and wear tester.
Findings
Enhanced wear resistance was clearly obtained after functionalization of TiO2 film on aluminum by stearic acid.
Originality/value
The relevant results might be helpful for guiding the surface modification of aluminum devices in industrial applications.
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Yuankai Zhou, Xue Zuo and Hua Zhu
Running-in is a transient process prior to steady state and of great importance for mechanical performance. To reveal the fractal behavior in the running-in process, the…
Abstract
Purpose
Running-in is a transient process prior to steady state and of great importance for mechanical performance. To reveal the fractal behavior in the running-in process, the steel-on-steel friction and wear tests were performed.
Design/methodology/approach
The friction coefficient, friction temperature, friction noise and vibration were recorded, and the surface profile of lower sample was measured on line. The signals and profiles were characterized by correlation dimension and box-counting dimension, respectively.
Findings
The signals have the consistent fractal evolvement law, that is, the correlation dimension increases and tends to a stable value. The box-counting dimension of one surface becomes close to that of the other surface. The running-in process can be interpreted as a process in which the fractal dimension of friction signals increases, and the counter surfaces spontaneously adapt to and modify each other to form a spatial ordered structure.
Originality/value
The results reveal the running-in behavior from a new perspective.
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Marlon José Cardoso, Milton Luiz Polli and Giuseppe Pintaude
Deep drilling of hardened steels is a difficult machining operation because of the high wear level of tools. This paper aims to present the main wear mechanisms observed in…
Abstract
Purpose
Deep drilling of hardened steels is a difficult machining operation because of the high wear level of tools. This paper aims to present the main wear mechanisms observed in physical vapor deposition (PVD)-coated twist drills during deep drilling of SAE4144M steel under minimum quantity lubrication, assessed in the production of injection holders.
Design/methodology/approach
Two PVD coatings were tested: TiAlN and AlCrN, industrially processed, the last one being a multilayer coating. The workpiece was heat treated for a hardness of 39 HRC to be applied in a diesel engine component. The tests were performed in an industrial environment for a fixed number of holes. Two levels of cutting speed and feed rate were selected for the experiments. In addition, minimum quantity of lubrication (MQL) was compared with conventional lubrication. Scanning electron microscope was used to reveal the wear mechanisms.
Findings
Spalling of PVD-coating was revealed for conventional lubrication, while adhesion was observed in MQL conditions. The use of multilayered AlCrN-based coating promoted a significant reduction of adhered material on the twist drill, which is the reason for this selection in industrial operation.
Practical implications
Results showed that the MQL regime can be applied for this industrial application.
Originality/value
A detailed description of wear mechanisms, which allows a suitable selection of coating and machining variables was found for a very difficult operation, using a more economic process in terms of lubrication.
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Dawit Zenebe Segu and Pyung Hwang
– The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance.
Abstract
Purpose
The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance.
Design/methodology/approach
The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface.
Findings
The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions.
Originality/value
This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.
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Muhamad Zamri Yahaya and Ahmad Azmin Mohamad
This paper aims to cover the recent (2010-2016) techniques for carrying out hardness evaluation on lead-free solders. Details testing configuration/design were compiled and…
Abstract
Purpose
This paper aims to cover the recent (2010-2016) techniques for carrying out hardness evaluation on lead-free solders. Details testing configuration/design were compiled and discussed accordingly to each of the measurement techniques: Vickers microhardness, Brinell microhardness and nanoindentation.
Design/methodology/approach
A brief introduction on lead-free solders and the concept of hardness testing has been described at the beginning of the review. Equipment setup, capabilities, test configuration and outcomes were presented for each technique and discussed in parallel along with the case studies from selected articles.
Findings
Comparison, outcomes and insight regarding each of the methods were highlighted to observe the recent trends, scientific challenges, limitations and probable breakthroughs of the particular hardness testing methods.
Originality/value
The compilation of latest reports, technical setup plus with the critics and perception from the authors are the main key value in this review. This provides an in-depth understanding and guidance for conducting hardness evaluation on lead-free solders.
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Vijayasarathi Prabakaran, Ilaiyavel S., SureshPrabhu P. and Sornakumar Samuel Thambu
In this study the microstructure and wear characteristics of Multilayer AlCrN coated AISI 410 stainless steel with the physical vapor deposition technique.
Abstract
Purpose
In this study the microstructure and wear characteristics of Multilayer AlCrN coated AISI 410 stainless steel with the physical vapor deposition technique.
Design/methodology/approach
The friction and wear performance of the ML-AlCrN-coated AISI410 steel and uncoated AISI410 steel sliding against with high carbon steel were investigated by the ball cratering test at room temperature. The tribological characteristic of coated AISI410 steel was determined by applying constant sliding velocity of 0.3927 ms−1 and total sliding distance of 353.43 m over various normal loads of 2, 3 and 4 N.
Findings
The AlCrN-coated AISI410 steel showed excellent wear performance up to 4 N load. The uncoated AISI410 steel showed good to acceptable wear resistance up to 2 N load. The wear tracks and worn surface were examined by scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS) attachment for explaining the differences in wear mechanism.
Originality/value
The ability of coating to delay substrate oxidation, with an excellent wear resistance, was identified under different parameters on worn areas.
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Xiangxia Kong, F. Sun, Miaosen Yang and Yang Liu
This paper aims to investigate the creep properties of the bulks of low-Ag Cu/Sn-Ag-Cu-Bi-Ni/Cu micro solder joints from 298 to 358 K. The creep constitutive modelling was…
Abstract
Purpose
This paper aims to investigate the creep properties of the bulks of low-Ag Cu/Sn-Ag-Cu-Bi-Ni/Cu micro solder joints from 298 to 358 K. The creep constitutive modelling was developed. Meanwhile, the creep mechanism of the bulks of Cu/Sn-Ag-Cu-Bi-Ni/Cu micro solder joints was discussed.
Design/methodology/approach
The creep properties of the bulks of low-Ag Cu/Sn-Ag-Cu-Bi-Ni/Cu micro solder joints from 298 to 358 K were investigated using the nanoindentation method.
Findings
The results of the experiments showed that the indentation depth and area increased with increasing temperatures. At the test temperature of 298-358 K, the creep strain rate of the bulks of the micro solder joints increases with the rising of the tested temperature. The values of creep stress exponent and activation energy calculated for the bulks of Cu/Sn-Ag-Cu-Bi-Ni/Cu micro solder joints were reasonably close to the published data. At the tested temperatures, dislocation climb took place and the dislocation climb motion was controlled by the dislocation pipe mechanism, and the second-phase particles enhancement mechanism played a very important role.
Originality/value
This study provides the creep properties of low-Ag Cu/Sn-Ag-Cu-Bi-Ni/Cu solder joints at different temperatures. The creep constitutive modelling has been developed for low-Ag Cu/Sn-Ag-Cu-Bi-Ni/Cu solder joints.