G. Yoganjaneyulu, Y. Phaneendra, V.V. Ravikumar and C. Sathiya Narayanan
The purpose of this paper is to investigate the void coalescence and corrosion behaviour of titanium Grade 4 sheets during single point incremental forming (SPIF) process with…
Abstract
Purpose
The purpose of this paper is to investigate the void coalescence and corrosion behaviour of titanium Grade 4 sheets during single point incremental forming (SPIF) process with various spindle rotational speeds. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during SPIF process.
Design/methodology/approach
In this current research work, the void coalescence analysis and corrosion behaviour of titanium Grade 4 specimens were studied. A potentio-dynamic polarization (PDP) study was conducted to investigate the corrosion behaviour of titanium Grade 4 processed samples with various spindle speeds in 3.5 (%) NaCl solution. The scanning electron microscope and transmission electron microscope analysis was carried out to study the fracture behaviour and corrosion morphology of processed samples.
Findings
The titanium Grade 4 sheets obtained better formability and corrosion resistance by increasing the CNC spindle rotational speeds. In fact that, the significant plastic deformation affects the corrosion rate with various spindle speeds were recorded.
Originality/value
The spindle rotational speeds and vertical step depths increases then the titanium Grade 4 sheets showed better formability, void coalescence and corrosion behaviour as the same is evidenced in forming limit diagram and PDP curves.
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Keywords
G. Yoganjaneyulu, V.V. Ravikumar and C. Sathiya Narayanan
The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental…
Abstract
Purpose
The purpose of this paper is to investigate the strain distribution, stress-based fracture limit and corrosion behaviour of titanium Grade 2 sheets during single point incremental forming (SPIF) process, with various computerized numerical control (CNC) spindle rotational speeds and step depths. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during the SPIF process.
Design/methodology/approach
A potentiodynamic polarization (PDP) study was performed to investigate the corrosion behaviour of titanium Grade 2 deformed samples, with various spindle rotational speeds in 3.5 (%) NaCl solution. The scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis was carried out to study the fracture behaviour, dislocation densities and corrosion morphology of deformed samples.
Findings
The titanium Grade 2 sheets exhibited better strain distribution, fracture limit and corrosion resistance by increasing the CNC spindle rotational speeds, tool diameters and vertical step depths (VSD). It was recorded that varying the spindle speed affected plastic deformation which in turn affected corrosion rate.
Research limitations/implications
In this study, poor corrosion rate was observed for the as-received condition, and better corrosion rate was achieved at maximum speed of 600 rpm and 0.6 mm of VSD in the deformed sheet. This indicates that corrosion rate improved with increase in the plastic deformation. The EDS analysis report of corroded surface revealed the composition to be mainly of titanium and oxides.
Practical implications
This study discusses the strain distribution, stress-based fracture limit and corrosion behaviour by using titanium Grade 2 sheets during SPIF process.
Social implications
This study is useful in the field of automobile and industrial applications.
Originality/value
With an increase in the spindle rotational speeds and VSD, the titanium Grade 2 sheets showed better strain distribution, fracture limit and corrosion behaviour; the same is evidenced in fracture limit curve and PDP curves.
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Shaik Heruthunnisa and Chandra Mohana Reddy B.
The purpose of this paper is to study formability, tensile properties, dislocation density and surface roughness of incrementally deformed Ti–6Al–4V alloy sheets during…
Abstract
Purpose
The purpose of this paper is to study formability, tensile properties, dislocation density and surface roughness of incrementally deformed Ti–6Al–4V alloy sheets during single-point incremental forming (SPIF) and multi-point incremental forming (MPIF) process. The development of corrosion pits in 3.5% NaCl solution has also been studied during SPIF and MPIF processes.
Design/methodology/approach
In this study, the formability, tensile properties, dislocation density, surface roughness and corrosion behaviour of deformed Ti–6Al–4V alloy sheets were studied. A potentio-dynamic polarization (PDP) study was conducted to study the corrosion behaviour of Ti–6Al–4V alloy samples during SPIF and MPIF processes and the results were also compared with base material (BM) in 3.5% NaCl solution. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses were carried out to study the corrosion morphology and dislocation densities of deformed samples.
Findings
The deformed Ti–6Al–4V alloy sheets obtained higher plastic deformation, high tensile strength, good surface roughness and good corrosion resistance during MPIF process when compared with SPIF process.
Research limitations/implications
It has been concluded that the maximum strain and good corrosion resistance have been achieved with MPIF process, which in turn increases the plastic deformation as compared with BM.
Practical implications
This study discussed the formability, tensile properties, surface roughness and corrosion behaviour of deformed Ti–6Al –4V alloy sheets during incremental sheet forming (ISF) process.
Social implications
This study is useful in the field of medical, industrial and automobile applications.
Originality/value
The Ti–6Al–4V alloy is deformed using MPIF process, achieving better formability, tensile strength, good surface roughness and corrosion rate, and the same is evidenced in forming limit diagrams (FLDs) and PDP curves.
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Baskara Sethupathi P. and Chandradass J.
This study aims to compare the influence of different solid lubricants on the friction stability of a non-asbestos disc brake pad.
Abstract
Purpose
This study aims to compare the influence of different solid lubricants on the friction stability of a non-asbestos disc brake pad.
Design/methodology/approach
Three brake pads were developed using three lubricants, namely, non-asbestos brake pad with sulfide mix (NASM), non-asbestos brake pad with bismuth sulfide (NABS) and non-asbestos brake pad with molybdenum disulfide (NAMO). Sulfide mix was indigenously developed by physically mixing friction modifiers, alkaline earth chemicals and various metallic sulfides homogeneously dispersed in graphite medium. The physical, chemical, mechanical and thermal properties of brake pads were characterized as per industrial standards. The tribological performances were studied using the Chase testing machine as SAE-J661-2012. The worn surface of the pads was studied using scanning electron microscope to analyze the dominating wear mechanism.
Findings
NASM was excellent in fade as well as wear resistance. NABS was better from a wear point of view, but fade resistance was moderate despite its higher cost. NAMO fared average in fade and wear despite its excellent dry lubricating properties. NASM was excellent in terms of fade as well as wear resistance.
Originality/value
Among the selected metal sulfides, the indigenously developed sulfide mix was better than the other two sulfides, which indicates that the synergetic effect of metal sulfides was always preferable to the individual sulfides.
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Zhong Li, Xiaojia Yang, Jing Liu, Zhiyong Liu, Xiaogang Li and Yan Tingting
The purpose of this paper is to determine the failure reasons and failure mechanism of the commercially pure titanium air conditioning condenser.
Abstract
Purpose
The purpose of this paper is to determine the failure reasons and failure mechanism of the commercially pure titanium air conditioning condenser.
Design/methodology/approach
In this paper, chemical analysis, metallographic observation, visual examination and scanning electron microscope examination, corrosion products analysis and working conditions analysis were adopted for determining the reasons for the failure of the condenser.
Findings
The results indicated that TA2 titanium pipe perforation failure is caused by the synergistic effect of crevice corrosion and deposit corrosion. The corrosion processes can be divided into three steps.
Originality/value
This research is an originality study on the failure case of a commercially pure titanium air conditioning condenser. This study makes up for the shortage of titanium alloy failure cases and also gives the result of the failure reason and failure mechanism for titanium, which has an engineering significance.