Browsing by Author "Senevirathne, SWMAI"

Now showing 1 - 8 of 8

item: Conference-Extended-Abstract
Development of die & mould making industry in Sri Lanka though tripartite collaboration of university-industry-government
(2009) Senevirathne, SWMAI; Kahangamage, UP; Mangala, KHJ
Most of the Sri Lankan Die & mould makers are Small and Medium Enterprises. Due to various constraints they manage cater only for 20% of local die & mould demand. One of the reasons is the high technological gap between SMEs scale mould makers The local SME mould makers need financial and technological support to increase production and the quality. Considering the strengths and weaknesses of different parties, a tripartite approach that involves the government and the academic institutes has been proposed to uplift this industry. This paper presents a proposed mode! for a tripartite approach and its successful implementation being carried out at University of Moratuwa.
item: Thesis-Full-text
Effect of air and chilled emulsion minimum quality lubrication (ACEMQL) in machining hard to cut metals
Senevirathne, SWMAI; Punchihewa, HKG
Effect of Air and Chilled Emulsion Minimum Quantity Lubrication in Machining Hard to Cut Metals A novel approach of cutting fluid application was developed and its performance in machining hard to cut metalswas investigated. The study focused on turning AISI P20 and D2 tool steels using coated carbide cutting tools. For this study, an improved minimum quantity lubrication (MQL) method named, air and chilled emulsion minimum quantity lubrication (ACEMQL) method was developed to evaluate its effect on tool life and surface finish of material being machined. Trials were carried outfor ACEMQL with cutting fluid temperatures from 5°C to 20 °C in steps of 5 °C.In order to obtain a benchmark for comparison ofresults, set oftrials were carried out for dry cutting and flood cooling at 25 °C while all other parameters kept same as in ACEMQL method. Trials for ACEMQL method resulted in better tool life and surface finish for both AISI P20 and AISI D2 tool steels when compared with dry cutting and regular flood cooling methods. Minimum tool wear in machining AISI P20, was observed at 15 °C with ACEMQL, and it has shown a trend of increasing tool wear when temperature was lowered to 10 °C and 5 °C. A tool wear reduction of 97% from dry cutting, and 93% of flood cooling, is observed with ACEMQL at 15 °C. At 10 °C also ACEMQL has shown a reduction in tool wear by 94% compared with dry cutting and 86% compared with flood cooling. However, at 20 °C, it is observed that there is an increase in tool wear compared to flood cooling by 29%. Similarly, in machining AISI D2, minimum tool wear was observed at 15 °C with ACEMQL, and it has shown a trend of increasing tool wear when temperature was further lowered to 10 °C and 5 °C. A tool wear reduction of 96% from dry cutting, and 93% offlood cooling, is observed with ACEMQL at 15 °C. At 10 °C also ACEMQL has shown a reduction in tool wear by 71% compared with diy cutting and 57% compared with flood cooling. Although use of ACEMQL shows an improvement in surface finish in machining both AISI P20 and D2, it has not shown significant difference with reduction oftemperature in the investigated steps oftemperatures. For AISI P20, the least surface roughness obtained is 0.97 pm Ra and it is at 5 °C. It is a 35% reduction with respect to dry cutting condition and 31% reduction in comparison with flood cooling condition. For AISI D2, the minimum surface roughness obtained is 0.82 pm Ra and it is at 5 °C. It is a 49% reduction with respect to dry cutting condition and 40% reduction in comparison with flood cooling condition.Research on the effect of cutting velocity, feed rate and depth of cut, on tool life and surface finish with ACEMQL is suggested as future work. Further, economic feasibility analysis is suggested to find out the suitability of ACEMQL in local die and mould manufacturing industry, and also research on relationship between chip colour and cutting condition, and reasons for the colourisation is suggested as future work.
item: Conference-Full-text
Effect of cryogenic cooling on machining performance on hard to cut metals - a literature review
(2013) Senevirathne, SWMAI; Fernando, MARV
This paper presents a literature review done on Cryogenic cooling, Liquid Nitrogen Cooling(LNC), and 'Chilled Air and Minimum Quantity Lubrication' (CAMQL) cooling methods used in machining operations, targeting to recognise better cooling methods for the Sri Lankan die and mould making sector (SLDMMS). The state of the art in cryogenic machining was searched and reviewed first, and then its benefits, limitations, and applications were studied. Alternative cooling methods for conventional emulsion cooling were searched. The benefits from cryogenic cooling and other alternative methods were analysed and compared. LNC and CAMQL cooling were chosen as subjects for further comparative study. A substantial amount of literature was found on the effect of these cooling methods on hard-to-cut materials such as lnconel, Titanium alloys etc., but very few or no studies had been carried out on materials used in the Sri Lankan die and mould making sector. A survey on materials used in SLDMMS is recommended to identify the most commonly used material types. An economic feasibility study of cryogenic cooling and chilled air cooling is recommended.
item: Conference-Full-text
Effect of cryogenic cooling on machining performance on hard to cut metals - a literature review
(The Engineering Research Unit, University of Moratuwa, 2013-02) Senevirathne, SWMAI; Fernando, MARV; Rodrigo, R
This paper presents a literature review done on Cryogenic cooling, Liquid Nitrogen Coot,ng(LNC) and •Chilled Air and Minimum Quantity Lubrication (CAMQL) cooling methods used ,n targeting to recognise belter cooling methods for the Sri Lankan d,e and mould making sector (SLDMMS). The state of the art in cryogenic machining was searched and reviewed first, and then its benefits, limitations and applications were studied. Alternative cooling methods for conventional emulsion cooling were seai ched. The benefits from cryogenic cooling and other alternative methods were analysed and compared. LNC and CAMQL cooling were chosen as subjects for further comparative study. A substantial amount of literature was found on the effect of these cooling methods on hard-to-cut materials such as Inconel, Titanium alloys etc., but very few or no studies had been carried out on materials used in the Sri Lankan die and mould making sector A survey on materials used in SLDMMS is recommended to identify the most commonly used material types. An economic feasibility study of cryogenic cooling and chilled air cooling is recommended.
item: Conference-Full-text
Effect of minimum quantity lubrication aerosol temperature on tool life in machining aisi p20 and d2 steels using coated tungsten carbide tool inserts
(IEEE, 2016-04) Senevirathne, SWMAI; Punchihewa, HKG; Jayasekara, AGBP; Bandara, HMND; Amarasinghe, YWR
This study focused on turning AISI P20 and D2 tool steels using coated-carbide cutting tools. In this experimental investigation, an emulsion cutting fluid (CF) aerosol temperature with minimum quantity lubrication (MQL) was varied from 5 oC to 20 oC and its effect on the tool life was evaluated. Trials were done for dry cutting and flood cooling at 25 oC also in same conditions. MQL revealed better tool life for both steels than dry cutting and flood cooling. The tool wear for P20 showed a quadratic behaviour against aerosol temperature, with minimum occurred at 15 oC. At 15 oC, 97% and 93% tool wear reductions were observed from dry cutting and flood cooling respectively. However at 20 oC, tool wear increased by 29% from flood cooling. For D2 steel, similar characteristics were observed with minimum wear at 15 oC. A wear reduction of 96% from dry cutting, and 93% from flood cooling was observed with at 15 oC. MQL at 15 oC leads to a potential means of reducing machining costs. However, trials need to be repeated with different tool material, work-piece material and aerosols to ascertain the generalizability of the findings.
item: Conference-Abstract
Investigation & simulation of bird flight kinematics & dynamics
(2008) Senevirathne, SWMAI; Piyathilake, BAV; Perera, BDAS; Perera, PABAR; Fernando, MARV
Birds use a simple technique to get airborne. However, mankind is still not capable of using this simple technique successfully in any applications. In this project, it has been investigated about bird flight kinematics with respect to the different flying patterns of birds, with the intension of developing a mechanism for human applications which uses such kinematics. Motions of bird wing skeleton were examined and analysed using computer software. Virtual simulations of wing patterns were also done. In addition, an innovative simulation method has been developed to acquire flapping motion by manipulation of aerodynamic forces exerted, which has minimised the number of prime movers on board.
item: Conference-Full-text
Process optimization of Sri Lankan saucepan manufacturing industry by time study analysis
(2015-07-09) Gayan, RBA; Rameshkanna, Y; Ratheesan, R; Senevirathne, SWMAI; Mangala, KHJ; Bandara, DSV
This study was carried out at the Jayantha Saucepan Industry to improve and enhance the productivity by reducing the idle time and enhance the bottleneck by different methods such as changing the layouts, changing the number of work stations and changing the process flow. During the study, it investigated and searched for possible solutions and alternatives aimed at achieving the objective by Pareto analysis for time study, allocating the work stations in an effective way, changing the layout for a better productivity, and analysing skill matrix to allocate the works for the current labourers, and train the labourers and need of hiring more labourers for the particular work stations in an efficient way to enhance the bottleneck manually. Further improvements such as adapting into new techniques and using better alternatives for some processes were also discussed to enhance the productivity of the local saucepan manufacturing industry. Overall, suggested alternatives yielded an expected improvement of 20% in the production capacity
item:
Reducing surface roughness by varying aerosol temperature with minimum quantity lubrication in machining AISI P20 and D2 steels
(Springer, 2018) Senevirathne, SWMAI; Punchihewa, HKG
Heat generation in metal cutting leads to numerous problems. Despite the development of many different cooling and lubrication methods in industry, opportunities are still open to develop novel methods. Minimum quantity lubrication (MQL) is a recent such development that has shown promising results. However, the effect of aerosol temperature on machining performance has not yet been studied in depth. Thus, the aim of this study is to explore the ability to improve surface roughness in machining by lowering the MQL aerosol temperature. To study the effect of the aerosol temperature in MQL, an experimental investigation is carried out using a simple turning operation on AISI P20 and D2 steels, with cutting tools and cutting fluids (CF) typically used in industry. The arithmetic average surface roughness of the workpiece is measured for each of the treatments. Measurements are taken with dry cutting condition, conventional flood cooling method, and several MQL temperatures. Significantly lower surface roughness in the workpieces is observed for all considered MQL temperatures in comparison to dry cutting and flood cooling conditions. Furthermore, a reducing trend with a quadratic behaviour in surface roughness is observed with decreasing temperatures. The lowest surface roughness is observed at MQL 5 °C for both material. Interestingly, the effect of aerosol temperature is observed to be high with D2 steel and lower temperatures achieved up to 50% reduction in surface roughness. The study concludes that surface roughness can be reduced using low-temperature MQL. The effect of the aerosol temperature on other tool-work material combinations and tribology studies are suggested as further work.