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Srinivasa, C. K.
- Studies on Micro-Electrical Discharge Machining of Steel Using Copper Electrodes
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore, IN
Source
Manufacturing Technology Today, Vol 14, No 1 (2015), Pagination: 9-13Abstract
Electrical Discharge Machining (EDM) is one of the non-conventional machining processes used for machining of electrically conductive materials. Mechanism of material removal in EDM is based on conversion of electrical energy into thermal energy. In this paper, copper electrodes of diameter 0.1, 0.4 and 0.8 mm were used for machining holes on steel work-piece to a depth of 0.2 mm by micro-EDM process. Experiments were conducted at a capacitance of 0.001, 0.01, 0.1 and 0.4 μF with a gap voltage of 80 V and the electrode was rotated at 100 rpm during ED machining. Wear on the electrode; surface roughness and the size of the machined hole were measured. Capacitance had a profound influence on the material removal rate, volumetric wear ratio, spark gap and surface roughness of work-piece.Keywords
EDM, Micro-Holes, Electrodes, Wear, Capacitance, Spark Gap.
- Effect of Cryogenic Cooling in Turning Ss304 Using Coated Carbide at High Cutting Speeds
Authors
1 Central Manufacturing Technology Institute, Bangalore-560022, IN
Source
Manufacturing Technology Today, Vol 13, No 6 (2014), Pagination: 16-19Abstract
In the present work machining of SS304 was carried out on a lathe using coated carbide tool at high cutting speeds. The effect of cryogenic cooling on tool life and cutting forces were analyzed and compared with conventional flood coolant. Tests were carried out at cutting speed of 200 and 250 m/min, and the feed rate, depth of cut were kept constant at 0.2 mm/rev and 1.5 mm respectively. Coated carbide CNMG 120404 Insert was used as a cutting tool. The results have revealed that cryogenic machining has yielded better tool life as compared to conventional flood machining.Keywords
Cryogenic Machining, Tool Life, Cutting Forces, Coated Carbide Tool.- Deposition of Bronze-Nickel on Steel by Laser-Based Metal Deposition Process
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore, IN
Source
Manufacturing Technology Today, Vol 13, No 1 (2014), Pagination: 27-30Abstract
Direct Metal Deposition (DMD) is an additive manufacturing process for fabrication of metal parts directly from CAD model using high power lasers as heat source. In this paper, bronze nickel material was deposited on steel substrate by DMD process. Laser power was varied from 100 to 300 W in steps of 50. Laser scan speed, powder flow rate, nozzle stand-off and step-over were maintained at 165 mm/min, 1.2 g/min, 10 mm and 0.15 mm respectively. Laser power had a significant influence on the quality of joint between bronze nickel and steel.Keywords
Additive Manufacturing, DMD, Laser, Dissimilar Materials.- Metal Injection Molding - A Review
Authors
1 Madanapalle Institute of Technology and Science, Madanapalle, IN
2 J.N.T.U.A.College of Engineering, Anantapuramu, IN
Source
Manufacturing Technology Today, Vol 15, No 12 (2016), Pagination: 3-10Abstract
Metal Injection Molding (MIM) is relatively a new technology for producing metal components of complex geometry. MIM is an extension of powder metallurgy process. Various products of metals and its alloys including difficult-to-machine materials such as titanium, tungsten etc., can be effectively manufactured by MIM process. MIM process comprises of four steps; mixing of metal powders with binders, injection molding of coated-metal powders to produce green parts, de-binding to separate binders from green part and the final stage is sintering. The process parameters in mixing, injection molding, de-binding and sintering play a vital role in the quality of final product.
This paper is aimed at reviewing the MIM process parameters and materials.
Keywords
MIM, Green Part, Sintering, Binder, Metal Powders, Mixing, De-Binding.References
- Moballegh, L; Morshedian, J; Esfandeh, M: Copper injection molding using a thermoplastic binder based on paraffin wax, 'Materials Letters', vol. 59, no. 22, 2005, 2832-2837.
- Liu, ZY; Loh, NH; khor, KA; Tor, SB: Sintering of injection molded M2 high-speed steel, 'Material Letters', vol. 45, no. 1, 2000, 32-38.
- Ozgun, Ozgur; Gulsoy, H Ozkan; Yilmaz, Ramazan; Findik, Fehim: Injection molding of nickel based 625 superalloy: Sintering, heat treatment, microstructure and mechanical properties, 'Journal of Alloys and Compounds', vol. 546, 2013, 192-207.
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- Luo, TG; Qu, XH; Qin, ML; Ouyang, ML: Dimension precision of metal injection molded pure tungsten, 'Int. Journal of Refractory Metals & Hard Materials', vol. 27, no. 3, 2009, 615-620.
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- Li, Duxin; Hou, Haitao; Tan, Zhaoqiang; Lee, Kun: Metal injection Molding of pure Molybdenum, 'Advanced Powder Technology', vol. 20, no. 5, 2009, 480-487.
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- Loh, NH; Tor, SB; Khor, KA: Production of metal matrix composite part by powder injection molding, 'Journal of materials processing technology', vol. 108, no. 3, 2001, 398-407.
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- Shu-quan, Liang; Yan, Tang; Bai-yun, Huang: Rheology in metal powder injection molding, J.Cent . South Univ. Technol., 2007, sl-0372-06
- Corrosion Behavior of Iron and Iron-SiC Composites Produced by DMLS Process
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore, IN
2 Dept of Mechanical Engg., PES Institute of Technology, Bangalore, IN
Source
Manufacturing Technology Today, Vol 8, No 9 (2009), Pagination: 3-7Abstract
Iron and iron-SiC (NiP-coated) composites with 1, 2, 3 and 5 wt % of SiC, were produced by Direct Metal Laser Sintering (DMLS) p rocess. Sintering parameters namely the laser power, hatch width, hatch spacing and layer thickness were maintained at 180W, 5mm, 0.2mm, 0.05mm respectively while the laser scan speed was varied from 50 to I25mm/s in steps of 25. Salt spray test method was adopted to study the corrosion behaviour of laser-sintered parts. Salt spray tests were conducted in 5.0 % NaCl solution for durations of 24, 48 and 72 hours. Laser scan speed and wt. % of SiC had a significant influence on the density and corrosion behaviour of sintered iron and its composites. At all test durations studied, iron-SiC (NiP-coated) composites have exhibited excellent corrosion resistance when compared with iron.- Design of Prototypes & Injection Mould Tooling for Manufacturing by Direct Metal Laser Sintering (DMLS) Technology
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore-560 022, IN
Source
Manufacturing Technology Today, Vol 1, No 3 (2002), Pagination: 5-9Abstract
Generally, Prototypes & injection mould toolings are produced by conventional, Computer Numerical Control (CNC) machining & electrical discharge machining processes. Making moulds by these methods is slow and expensive for low batch quantities. Product complexity is increasing & product cycles are growing ever shorter Therefore Rapid Prototyping (RP) tooling fabrications should be considered for projects in which the reduction of time to market is important, for prototypes and short to medium volume production runs.
At least six different Rapid Prototyping technologies are commercially available in the market. Direct Metal Laser Sintering (DMLS) is one such Rapid Prototyping technology for producing prototypes & toolings for injection moulding & investment casting processes using metal powder (Bronze Nickel). EOSINT M250 machine from M/s EOS Gmbh-Germany is a direct metal laser-sintering machine.
Each manufacturing process has its advantages and limitations from the point of accuracy, shape, surface finish & cost. This paper deals with the brief description of EOSINT M250 RP machine, process, design rules for parts, accuracy surface finish & geometry of parts that are best suited for DMLS technology from the point of cost and time.