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3D printing of carbon nanofiber‐PLA composite

- Msibi, M., Mashamba, A., Mashinini, P. M., Hashe, V. T.

  • Authors: Msibi, M. , Mashamba, A. , Mashinini, P. M. , Hashe, V. T.
  • Date: 2018
  • Subjects: Carbon nanofiber , Poly(lactic acid) , Polylactide (PLA)
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/278523 , uj:29889 , Citation: Msibi, M. et al. 2018. 3D printing of carbon nanofiber‐PLA composite. 11th South African Conference on Computational and Applied Mechanics, 17-19 Sept 2018.
  • Description: Abstract: The aim of this research study was to study the mechanical properties of carbon nanofiber (CNF) and Polylactide (PLA) composite. The composite material was developed by mixing Polylactide with carbon nano fiber using a three dimensional printer. The research study presents the following; the mixing ratios which were used, time intervals, mixing equipment and mixing method. After the composite material was developed, the mechanical properties of the material were studied. These mechanical properties include the ultimate tensile strength and yield strength between the two materials that is PLA and PCM composites. The effect of processing methods and conditions on the properties of CNF/PLA composites were also taken to consideration due to the impact they might have in the results obtained. An excel Anova software was also used to compare the UTS of the two materials and conclude if there is a significant difference between the parent material and the developed composite material. The Ultimate tensile strength improved by 4.16% from the initial ultimate tensile strength obtained from PLA samples, while the yield strength increased by 38.05% from the PLA. These results obtained conclude that the mechanical properties of the PCM have improved. At the end of the paper, recommendations of possible future challenges for CNF/PLA composites will be presented.
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Abrasive water jet cutting process form machining metals and composites for engineering applications : a review

- Khan, Adam M., Soni, Hargovind, Mashinini, P. M., Uthayakumar, U.

Analysis of defect formation during rotary friction welding of titanium alloy

- Zulu, M. C., Mashinini, P. M.

Analysis of the microstructure and microhardness of rotary friction welded titanium (Ti‐6AL‐V4) rods

- Mukhawana, D. M., Mashinini, P. M., Madyira, D. M.

Classification of defect formation during rotary friction welding of titanium alloy

- Zulu, M. C., Mashinini, P. M.

  • Authors: Zulu, M. C. , Mashinini, P. M.
  • Date: 2021
  • Subjects: Weld joint , Process parameters , Rotary friction welding
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/488315 , uj:44482 , Citation: Zulu, M.C. Mashinini, P.M.2021. Classification of defect formation during rotary friction welding of titanium alloy.
  • Description: Abstract: The weld defects are a constant problem to mechanical components of various applications. Defects may be the root cause of constant failure to critical components and may further create unsafe work environment in industries. Although friction welding process is a solid state welding technique, it is also susceptible to weld defects. The rotary friction welding of titanium alloy Ti-6Al-4V was conducted to investigate the formation of weld defects and their types. The microstructure analysis and visual inspection of weld joints was done to identify defects present in the welds of different welding parameters. Mechanical tests were also conducted to investigate the effect of defects in the properties of the weld joints. The common defects in rotary friction welding were observed. Flaws such as voids, excessive flash and discolouration were identified during the study and were linked to the unsuitable welding conditions. The tests conducted revealed that defects have a negative impact on the properties and quality of the weld joint. The relationship between defect and weld condition was studied. The study revealed that majority of the defects exist due to unsuitable combination of welding parameters utilised. Therefore, this paper presents the study of defects formation in the friction welding process of titanium alloy Ti-6Al-4V.
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Design and optimum process parameters for unique production cost

- Mashinini, P. M., Soni, H.

  • Authors: Mashinini, P. M. , Soni, H.
  • Date: 2021
  • Subjects: Stainless steel316 , Textured tool , Turning process
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/487204 , uj:44343 , Citation: Mashinini, P.M. & Soni, H. 2021. Design and optimum process parameters for unique production cost.
  • Description: Abstract: In the present study textured tungsten carbide cutting tool was used to machine on stainless steel 316 bar stock. Cutting velocity and feed rate with the range of 70-170 m/min and 0.1- 0.5 mm/rev respectively were chosen as input process parameters. The tool life and machining time are considered as responses for the proposed experiments. Unit production cost (USD) was calculated with standard assumptions. The investigation reports maximum tool life and minimum machining time required for defined volume of metal removal. Evolutionary algorithm was adopted to optimize the input parameters for minimum production cost. The optimal process parameter is 164.58 m/min cutting velocity, 0.5 mm/rev feed rate, 14.99 minutes tool life, 12.27 machining time were found for minimum unit production cost (9.26 USD).
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Dry sliding wear behavior of in-situ frabicated TiC particulate reinforced AA6061 aluminium alloy

- Selvam, J David Raja, Dinaharan, Isaac, Rai, Rajkumar S., Mashinini, P. M.

Enhanced process parameters using TOPSIS method during Wire electro discharge machining of TiNiCo shape memory alloy

- Soni, Hargovind, Narendranath, S., Ramesh, M. R., Mashinini, P. M.

  • Authors: Soni, Hargovind , Narendranath, S. , Ramesh, M. R. , Mashinini, P. M.
  • Date: 2020
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/411143 , uj:34538 , Citation: Soni, H. et al. 2020. Enhanced process parameters using TOPSIS method during Wire electro discharge machining of TiNiCo shape memory alloy.
  • Description: Abstract: Shape memory alloys (SMAs) are most usable material in the field of biomedical, aerospace and robotics applications due to their unique class of properties. Super elasticity, shape memory effect and two phase transformation behaviour of these alloys make unique material. Machining of such kind of material is quite difficult through conventional machining process hence non-conventional machining of these materials is suitable. Ti50Ni40Co10 shape memory alloy was developed through Vacuum arc melting furnace for the present study. Wire electro discharge machining (A Non-conventional Machining) was used for machining of Ti50Ni40Co10 shape memory alloy. Moreover Topsis method implemented for the parametric optimization of wire electro discharge machining (WEDM). Pulse on time, Pulse off time, Servo voltage, wire speed and servo feed were considered as process parameters and productivity rate and surface quality (average roughness) were consider as output process parameters of WEDM. To see the effect of machining on the machined component EDX analysis has been carried out of optimal process parameters setting. 4.72 mm3 /min productivity rate and 1.26 µm average roughness was found at optimal combination of process parameters of WEDM. Moreover, during the EDX analysis Cu, Zn, O and C were noticed on the machined surface including the parent material.
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Influence of laser heat input on weld zone width and fatigue performance of Ti-6Al-4V sheet

- Mashinini, P. M., Hattingh, D. G.

  • Authors: Mashinini, P. M. , Hattingh, D. G.
  • Date: 2020
  • Subjects: Laser beam welding , Ti-6Al-4V , Traverse speed
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/436161 , uj:37823 , Mashinini, P.M., Hattingh, D.G. 2020: Influence of laser heat input on weld zone width and fatigue performance of Ti-6Al-4V sheet .
  • Description: Abstract: , During this study, the fatigue life of laser welded Ti6Al4V sheet was evaluated as a function of process heat input. Heat input was varied by manipulating laser power and welding travel speed and was categorised into three heat input ranges (Low = 40 to 60 J/mm; Medium = 65 to 120 J/mm and High = 160 to 230 J/mm)). Fatigue data was acquired from as-welded and polished specimens in order to study the effect of weld geometry resulting from a change in process parameters. Results showed that there was an increase in fatigue life for low heat input welds, mainly derived from the associated higher traverse speeds, demonstrating that laser power variation was not the sole determinant in fatigue life. A higher fatigue life and lower heat input relationship is related to the occurrence of a narrower fusion zone and increased weld zone hardness that corresponds with a lower heat input obtained from higher traverse speeds. Two predominant crack initiation mechanisms were observed; internal initiation from discontinuities that is related to inadequate optimisation of welding process parameters for the polished samples, while surface initiation occurred in the welded specimens, due to the stress concentration effect of the weld bead geometry. An increase in welding speed or decrease in laser power both led to a reduction in weld undercut or a lower stress concentration at the weld toe. As expected the fatigue data for the polished samples showed a marked improvement in life and a reduction in scatter compared to the as-welded data.
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Influence of laser power and traverse speed on weld characteristics of laser beam welded Ti-6Al-4V sheet

- Mashinini, P. M., Hattingh D. G.

  • Authors: Mashinini, P. M. , Hattingh D. G.
  • Date: 2018
  • Subjects: Laser beam welding , Ti6Al4V , Traverse speed
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/273269 , uj:29109 , Citation: Mashinini, P.M. & Hattingh D.G. 2018. Influence of laser power and traverse speed on weld characteristics of laser beam welded Ti-6Al-4V sheet. Materials Research Proceedings 4 (2018) 59-64 doi: http://dx.doi.org/10.21741/9781945291678-9.
  • Description: Abstract: In this paper laser beam welding was used for joining 3 mm Ti-6Al-4V alloy sheets in a full penetration butt-weld configuration. Laser beam power and traverse speed were the only parameters varied in an attempt to characterize the influence on weld integrity with specific reference to residual stress and microstructural modifications. The iXRD residual stress data showed a definite influence of traverse speed on residual stresses, with low traverse speeds resulting in an increased tensile residual stresses in the longitudinal direction of the weld whilst in the transverse direction residual stress revealed a more compressive stress state. The residual stress data for this experiment compared favourably with published residual stresses data done by synchrotron X-ray diffraction. Weld joint integrity was further analyzed by evaluating the microstructure transformation in the weld nugget. These results revealed a degree of grain growth and the presences of fine acicular b (needle-like a) in prior b grain boundaries with increased traverse speed. Grain growth was predominantly influenced by the cooling rate which is associated with traverse speed. Additionally, the a-phase and b-phase were characterized in the various weld zones by electron backscatter diffraction (EBSD).
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Investigation of material wear formation on centrifugal fan impeller

- Mabunda, K. A., Mashinini, P. M.

Investigation of mechanical properties of friction and laser welded Ti-6Al-4V rods.

- Tlale, Thabo, Mashinini, P. M., Mukhawana, D. M.

Investigation on dry machining of stainless steel 316 using textured tungsten carbide tools

- Mashinini, P. M., Soni, Hargovind, Gupta, Kapil

  • Authors: Mashinini, P. M. , Soni, Hargovind , Gupta, Kapil
  • Date: 2020
  • Subjects: Machinability , MRR , Stainless steel
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/411192 , uj:34544 , Citation: P M Mashinini et al 2020 Mater. Res. Express 7 016502 , DOI: https://doi.org/10.1088/2053-1591/ab5630
  • Description: Abstract: In this research, austenitic stainless steel SS316 material has been machined using textured carbide cutting tools under dry conditions. Micro-textures were made on tool rake face using wire spark erosion machining technology. Effects of three important machining process parameters i.e. cutting speed, depth of cut and feed rate on machinability (MRR, average roughness, and tool wear) of SS316 have been investigated. Taguchi L27 orthogonal array based twenty seven experiments have been carried out by varying machining parameters at three levels. Feed rate has been identified as the most important parameter. Machining parameters have been optimized by grey entropy method to enhance the machinability. Optimal combination of machining parameters i.e. 170 m min−1 cutting speed, 0.5 mm/rev feed rate and 1.5 mm depth of cut produced the best machinability with 3.436 μm average roughness, 105187 mm3 min−1 . MRR, and tool wear 234.63 μm. Lastly, a tool wear and chip morphology study have been done where textured tools have been found outperformed plain (Non-textured) tools.
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Investigations on wire spark discharge and MRR using neural network modeling

- Mashinini, P. M., Soni, Hargovind

  • Authors: Mashinini, P. M. , Soni, Hargovind
  • Date: 2021
  • Subjects: Smart materials , Wire spark discharge machining , Metal removal rate
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/487213 , uj:44344 , Citation: Mashinini, P.M. & Soni, H. 2021. Investigations on wire spark discharge and MRR using neural network modeling.
  • Description: Abstract: TiNiCo alloy is a smart material that can recover its original shape when the temperature is increased or decreased. Due to its unique class of properties, such kinds of materials are used in various industrial applications such as robotics, biomedical and aerospace industries. conventional machining of these alloys is quite difficult hence non-conventional machining process are found to be more suitable for machining of these alloys. Wire sparks discharge machining process was chosen for the machining of Ti50Ni49Co1 and Ti50Ni45Co5 alloys. Pulse on the duration and servo voltage was selected as machining process parameters with their five levels and metal removal rate considered as machining response. The error analysis has been carried out through a comparison between experimental values and predicted values. An artificial neural network (ANN) was used as the prediction technique. Predicted values were found to be close to experimental values. 6 % error for Ti50Ni49Co1 and 5 % error have been found in Ti50Ni45Co5 alloy.
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Microstructure and mechanical characterization of in situ synthesized AA6061/(TiB2+Al2O3) hybrid aluminum matrix composites

- Selvam, J. David Raja, Dinaharan, I., Vibin Philip, S., Mashinini, P. M.

Microstructure and mechanical characterization of Nd : YAG laser beam welded AA6061/10 wt% ZrB2 aluminum matrix composites

- Selvam, J. David Raja, Dinaharan, I., Mashinini, P. M.

Microstructure evolution and mechanical characterization of friction stir welded titanium alloy Ti–6Al–4V using lanthanated tungsten tool

- Mashinini, P. M., Dinaharan, I., Selvama, J. David Raja, Hattingh, D. G.

Optimization of the surface quality in illing achine using PVC composite plate

- Ahirwar, Yashwant, Soni, Hargovind, Mashinini, P. M.

Process optimization of rotary friction welding of Ti-6Al-4V alloy rods

- Zulu, M. C., Mashinini, P. M.

  • Authors: Zulu, M. C. , Mashinini, P. M.
  • Date: 2018
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/279930 , uj:30071 , Citation: Zulu, M.C. & Mashinini, P.M. 2018. Process optimization of rotary friction welding of Ti-6Al-4V alloy rods.
  • Description: Abstract: This paper presents an investigation on the performance of rotary friction welded 25.4 mm diameter Ti-6Al-4V alloy rods. The process parameters used are friction and forging pressure, rotational speed, forging time and upset distance. The heating time was determined by the amount of friction pressure and rotational speed utilised. The final weld joints were examined for mechanical properties. The results revealed that friction welding process parameters have significant influence on the weld joint properties and weld joint integrity. The hardness and ultimate tensile properties of the weld joints varied with the variation in rotational speed and axial pressure. The tensile properties of the weld joints were higher than the parent material at lower rotational speed or higher axial pressure. The weld width was proportional to relative motion and inversely proportional to axial pressure.
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Role of zirconium diboride particles on microstructure and wear behavior of AA7075 in-situ aluminium matrix composites at elevated temperature

- Selvam, J. David Raja, Dinaharan, I., Rai, R. S., Mashinini, P. M.

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