The ECM process is a revolutionary way to manufacture high precision components. D. This layer is easily removed. Advantages of this process include: Design accuracy. Heat can cause problems in these materials. The ECM process is capable of machining metals and alloys irrespective of their strength and hardness. Match List I (Machining processes) with List II (Operating media) and select the correct answer using the codes given below the Lists: ... By which one of the following processes the metering holes in injector nozzles of diesel engines can be suitably made? Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. (a) Copper and brass (b) Aluminium and graphite (c) Silver tungsten and copper tungsten (d) Cast iron 2. 4. The process is used in aerospace engineering and the automotive, construction, medical equipment, microsystem and power supply industries. c) Wire and Sinker EDM both ECM can be used to generate internal profile of internal cam. EMAG provides a worldwide service network. In this p rocess, particles travel from the anodic material (workpiece) toward the cathodic material (machining tool). Machining can be used to create a variety of features including holes, slots, pockets, flat surfaces, and even complex surface contours. ECM can machine highly complicated and curved surfaces in a single pass. 4.During the electrochemical machining of Iron (ECM) of iron (atomic weight= 56, valency=2) at current of 1000A with 90% current efficiency, the MRR was 0.26gm/s.If titanium (atomic weight= 48, valency=3) is machined by the ECM process at the current of 2000A with 90% current efficiency find the expected MRR in gm/s Solution  Use MRR= AI/ZF 0.26= 56*900/F*2 F= 96923 … The traditional mechanical machining has a long history, it has played a great role in human production and material civilization. 2. a) Iron Generally aluminium, copper, brass, titanium, cupro-nickel and stainless steel are used as tool materials. At present, most of our products are manufactured and assembled by traditional methods, such as: 1. FHD (Fast Hole Drilling) EDM 1.4. Independent of workpiece hardness. Which of the following material can be machined using electronic discharge machine? Negligible tool wear. d) None of the mentioned Introduction Electrochemical Machining (ECM) is one of the newest and most useful non-traditional machining (NTM) process belonging to Electrochemical category. EMAG ECM provides electrochemical machining (ECM) technology and systems for the production of extremely hard materials and residue-free production of strategic workpieces. The removed material is precipitated from the electrolyte solution in the form of metal hydroxide. Workpiece material is removed only at precisely defined locations. Each of those parts require machining of extremely hard metals with certain mechanical specifications Some of these mechanical characteristics achieved by ECM are: Stress free grooves. Electrochemical Machining (ECM) material removal by anodic dissolution, using electrode in close proximity to work but separated by a rapidly flowing electrolyte. 1. All kinds of weapons and equipment: guns, canon, tanks, rockets, … You benefit from our speed and global networking. View Answer, 4. *Any groove geometry. 2. NaOH is generally the preferred electrolyte. You have questions or need detailed information? (b) Complex shapes can be easily machined. All electro-chemical machining processes are characterized by stress-free stock removal, gentle transitions and top-quality surfaces without burr formation. d) None of the mentioned It can be used for slotting very thin walled collets. ECM is used to machining disk or turbine rotor blade. Unlike other machining methods that place a cutting tool edge against raw metal, ECM uses chemicals and electricity to form the surface of the material to the desired configuration. Wire EDM 1.3. This can be used to create contours, ring ducts, grooves or bell hollows with no contact but very high precision. 2. Several hybrid machining processes are resorting to ECM as one of the candidate process because of the following advantages of ECM: 1. ECM can cut small or odd-shaped angles, intricate contours or cavities in hard and exotic metals, such as titanium aluminides, Inconel, Waspaloy, and high nickel, cobalt, and rhenium alloys. EDM – Electro Discharge Machining 1.1. ECM can also be used to generate internal profile of internal cams. What factors should be considered in selecting the tool materials in ECM? (2) Recast or white layer where EDM has altered the workpiece metallurgical structure. different work materials. To practice all areas of Manufacturing Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers. To name these are few are the losses created by an unwanted change for the master data like material master. Join our social networks below and stay updated with latest contests, videos, internships and jobs! Machining is a term used to describe a variety of material removal processes in which a cutting tool removes unwanted material from a workpiece to produce the desired shape. Tool:-A specially designed and shaped tool is used for ECM, which forms cathode in the ECM setup. a) Grinding machine b) Sinker EDM Machine tool - Machine tool - Electrical-discharge machining (EDM): EDM involves the direction of high-frequency electrical spark discharges from a graphite or soft metal tool, which serves as an electrode, to disintegrate electrically conductive materials such as hardened steel or carbide. Production of satellite rings and connecting rod, machining of gears and long profile etc. It can over-temper martensitic alloys, for example. Machining stainless steels dry is a little more difficult. b) To make the medium conducting They can provide surface finishes to Ra 0.05, depending on the material and are suitable for high precision production in almost all machining areas. Which of the following materials can be machined using Electro discharge machining? Complex shapes can be machined. Electrical discharge machining (EDM), also known as spark machining, spark eroding, die sinking, wire burning or wire erosion, is a metal fabrication process whereby a desired shape is obtained by using electrical discharges (sparks). As it is a contactless procedure with no heat input, the process is not subject to any of the disadvantages experienced with traditional machining methods, e.g. Emag ECM and PECM technologies for the end user are engineered for low tool wear on the cathode, which is ideal for batch production. Sanfoundry Global Education & Learning Series – Manufacturing Engineering. c) Electric discharge machine The removed material is precipitated from the electrolyte solution in the form of metal hydroxide. Advantages of this process include: Design accuracy. (c) There is almost negligible tool wear so cost of tool making is only one time investment for mass production. The Dynamic ECM process is a revolutionary way to manufacture high precision components. Which of the following material cannot be machined using electronic discharge machine? c) Decrease in melting point of work piece The machining can be carried out regardless of the structural condition of the metal and both soft and hard materials, including exotic metals, can be machined. Significant productivity gains can be achieved with machines for the production of engine parts, such as blisks. Drilling holes with high depth/diameter ratios, greater than 100:1 4. Electrochemical Machining Processes (ECM) Download: 17: Material Removal Rate of ECM: Download: 18: Electrode Double Layer: Download: 19: Material removal rate of an alloy in ECM: Download: 20: Kinematics and Dynamics of ECM: Download: 21: Temperature and Pressure rise during ECM… In an EDM machine, metal removal rate is 1.937 cubic mm / min. 4. A wide range of materials like steel, stainless steel, Ti and Ni super-alloys, aluminium as well as plastics, ceramics can be machined successfully using electron beam. c) 65 Tool Feed Rate: In ECM process, a gap of about 0.01 mm to 0.7 mm is maintained between the tool face and the work. It is normally used for mass production and is used for working extremely hard materials or materials that are difficult to machine using conventional methods. Workpiece material is removed only at precisely defined locations. c) 309 Which of the following is/are used as low wearing tool material(s) in electric discharge machining? Electrochemical machining (ECM) is used to remove metal and alloys which are difficult or impossible to machine … Also, while machined parts are typically metal, almost all materials can be machined, including metals, plastics, composites, and wood. Which of the following machine uses non conventional machining technique for metal removal? 20. View Answer, 9. A charge exchange takes place between the cathode and the anode in an aqueous electrolyte solution which targets specific areas of the workpiece. Advantages of this process include: Design accuracy. As can be seen the more brittle material is machined more rapidly. The wire may be guided horizontally or vertically. c) Decrease in current b) Rubber B. Material of workpiece is removed by anodic dissolution. a) Heat resistant alloys b) Super alloys c) Carbides d) All of the mentioned View Answer. The tool is usually made of copper, brass, stainless steel, and it is a mirror image of the desired machined cavity. View Answer, 6. Which of the following EDM machine is used for die cast tooling? 5. Aluminum, Brass, Bronze, copper, carbon, stainless steel and monel are a few of the material used for this purpose. a) Increase in melting point of work piece c) Wire and Sinker EDM both Advantages ECM offers impressive and long lasting advantages. Almost all kinds of metal can be electro-chemically machined, especially high-alloyed nickel- or titanium-based ones, as well as hardened materials. Similar to hole drilling and 2D structuring, several materials can be machined using TW-ECDM: glass, quartz, alumina [ 91,92,105 ], piezoelectric (PZT) ceramics [ 100,106 ], and various composites (glass- and Kevlar-epoxy) [ 58 ]. 3. Material removal rate in EDM increases with 2. Answer: d ... Advanced Machining Questions and Answers – ECM-Applications and Micro-ECM ; Complex shapes can be machined. You benefit from our speed and global branch offices. Please contact us! View Answer. The machine base, worktable and all other parts are constructed of corrosion-resistant, materials to avoid corrosion. The tool, i.e. View Answer, 7. Enhanced component longevity. Electro-Chemical Machining (ECM) is the generic term for a variety of electro-chemical processes. View Answer, 10. Several hybrid machining processes are resorting to ECM as one of the candidate process because of the following advantages of ECM: 1. Household appliances: refrigerators, washing machines, air conditioners, etc. 5. a) Flushing away the debris a) Increase in melting point of work piece Through controlled changes of the master using the ECM can improve the margins in a phased manner. Processes to be considered on difficult to machine materials 1.0. EMAG provides a worldwide service network. Conclusion b) 23 The ECM process is a revolutionary way to manufacture high precision components. The workpiece is typically cut from a larger piece of stock, which is available in a variety of standard shapes, such as flat sheets, solid bars, hollow tubes, and shaped beams. Independent of workpiece hardness. This set of Manufacturing Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Electric Discharge Machining”. v. Size, shape and material of the tool: The tool must match the required shape of the work-piece depending on the material and the profile to be produced. Only electrically conducting materials can be processed by ECM. ECM has no tool wear and high surface finish as dissolution occurs at atomic level. 1. View Answer, 8. ECM is used to machine workpieces through the anodic dissoultion of metal. In many austentic alloys, heat also does not flow well from the cutting zone into the chips because thermal conductivity tends to be low. Relative material removal rates (frequency = 16.3 kHz, amplitude = 12.5 um, grain size = 100 mesh) Work material Relative MRR Glass 100.0 Brass 6.6 Tungsten 4.8 Titanium 4.0 Steel 3.9 Chrome steel 1.4 © 2011-2020 Sanfoundry. Electrochemical machining (ECM) is a metal -removal process base d on the principle of reverse electroplating. b) 200 d) None of the mentioned Electrochemical Machining 1. b) Decrease in Current Complex and concave curvature parts can be produced easily by the use of convex and concave tools. d) None of the mentioned Electrical discharge machining (EDM), also known as spark machining, spark eroding, die sinking, wire burning or wire erosion, is a metal fabrication process whereby a desired shape is obtained by using electrical discharges (sparks). a) Iron b) Rubber c) Plastic d) Wood View Answer. The mechanism of material removal in EDM process is (a) Melting and Evaporation (b) Melting and … Dielectric medium in EDM is used for 5. The components are subjected to neither thermal nor mechanical stresses. Theoretically tool life is high 3. The components are subjected to neither thermal nor mechanical stresses. the cathode, is connected to a direct voltage source with the workpiece acting as the anode. 1. Electro-chemical machining is based on the principle of electrolysis. Acetal, PEEK and PVC plastic materials have superior machining characteristics, plus they resist melting and chipping while offering good dimensional stability. Instead of cutting metal using hardened tooling, material is removed more efficiently by an electrochemical process. ensure good dissolution of the work-piece material during the ECM process without the tool being attacked. *Any conductive metal can be machined. : The three layers are the following: (1) Spheres attached to the surface made of part material and electrode material that have spattered the surface. Only electrically conducting materials can be processed by ECM. Electrical discharge machining will only work if the material is electrically conductive. It is used for machining steam turbine blades within closed limits. Electrochemical Machining (ECM) Introduction . The machining can be carried out regardless of the structural condition of the metal and both soft and hard materials, including exotic metals, can be machined. Advantages of ECM Process: (а) Machining of hard and brittle material is possible with good quality of surface finish and dimensional accuracy. d) None of the mentioned ; 2. Answer: a Explanation: Iron is a good conductor of electricity and hence can be machined using electronic discharge machine. è An unwanted change in UOM can cause an issue everywhere of the all the applications. tool wear, mechanical stresses, micro-fissures caused by heat transfer or the need for subsequent deburring operations. Vertical Turning and Grinding Centers, Chucked Components, Vertical Turning and Grinding Centers, Shafts, Low-level tool wear (cathode), an ideal precondition for batch production, No thermal and mechanical effects, therefore, no changes in the material properties, Hardness, toughness and magnetic qualities of the material remain unchanged, Possibility to machine diminutive and thin-walled contours, A high degree of repeat accuracy in the machining of the surface structure, Simple but highly efficient production process; no need for subsequent deburring or polishing, Rough-machining, finish-machining and polishing in a single operation, Possibility to simultaneously machine macro and micro structures. Cutting depth is reproducible to <20 microns. ECM is often characterized as “reverse electroplating.” Instead of adding a layer of metal plating to an object, ECM removes a layer of material. Enhanced component longevity. Very small holes can be machined in every type of material with high accuracy 3. The tool is usually made of copper, brass, stainless steel, and it is a mirror image of the desired machined cavity. c) Copper ECM operation. Sinking EDM 1.2. ECM is capable of machining metals and alloys irrespective of their strength and hardness 2. Electro-chemical Machining Presented by: Keisham Sushima Devi DIP/14/ME/12 2. ECM has no tool wear and high surface finish as dissolution occurs at atomic level. c) To decrease the material removal rate View Answer, 5. View Answer, 2. 3. Electrochemical Machining Processes (ECM) Download: 17: Material Removal Rate of ECM: Download: 18: Electrode Double Layer: Download: 19: Material removal rate of an alloy in ECM: Download: 20: Kinematics and Dynamics of ECM: Download: 21: Temperature and Pressure rise during ECM… a) Wire EDM A single tool can be used to machine a large number of pieces without any loss in its shape and size. d) 402 No cutting forces are involved in ECM process 3. The two most common products of ECM are turbine/compressor blades and rifle barrels. b) Aluminum A specially designed and shaped tool is used. Tool materials used in +49 7162 17-4300 communicationsnoSpam@emaggroup.de. a) Iron Among its wide material application capabilities are even improved and tough to machine metal alloys irrespective of their hardness, strength or thermal properties. The ECM process is used for die sinking operation, profiling and contouring, drilling, grinding, trepanning and micro machining. b) Milling machine If total amount of material to removed is 600 cubic mm. Both external and internal geometries can be machined. d) Wood a) 80 Metals that can be machined with EDM include hastalloy, hardened tool-steel, titanium, carbide, inconel and kovar. In regard to ECM (electrochemical machining), which one of the following is NOT true? Further, those areas on the tool where ECM action is not required, should be insulated. Do you have questions or need more detailed information regarding this machine? b) Sinker EDM They may melt, chip, or go out of tolerance as you remove material. What are the various tool materials that can be used effectively with ECM? Yet, certain plastics remain tricky to machine. Time required in min will be View Answer, 3. During the process the metal work piece is dissolved (Machining) locally through electricity (Electro) and chemistry (Chemical) until it reaches the required complex 3D end shape. a) Wire EDM Material removal rate in EDM increases with 5. A. ECM is basically the reverse of electroplating. Instead of cutting metal using hardened tooling, material is removed more efficiently by an electrochemical process. Which of the following EDM machine is used for cutting shapes cut out of a flat sheet or plate of metal? Workpiece material is removed only at precisely defined locations. Phase Diagram, Mechanical Properties & Testing, Ferrous Metal, Non-Ferrous Metal & Heat Treatment, Magnetic & Electrical Properties of Material, Metrology, Welding & Fusion-Welding Processes, Powder Metallurgy, Metal Casting & Gating Systems, here is complete set of 1000+ Multiple Choice Questions and Answers, Prev - Manufacturing Engineering Questions & Answers – Surface Finishing Operations, Next - Manufacturing Engineering Questions & Answers – Electrochemical Machining, Digital Circuits Questions and Answers – Counter Implementation and Applications, Digital Circuits Questions and Answers – Up Down Counter, Agricultural Engineering Questions and Answers, Environmental Engineering Questions and Answers, Chemical Engineering Questions and Answers, Waste Water Engineering Questions and Answers, Engineering Chemistry I Questions and Answers, Engineering Materials and Metallurgy Questions and Answers, Engineering Metrology Questions and Answers, Best Reference Books – Technology, Engineering and Sciences, Instrumentation Engineering Questions and Answers, Fluidization Engineering Questions and Answers, Metallurgical Engineering Questions and Answers, Aeronautical Engineering Questions and Answers, Mechatronics Engineering Questions and Answers, Mechanical Engineering Questions and Answers, Machine Tools & Machining Questions and Answers, Manufacturing Engineering / Processes I Questions and Answers, Advanced Machining Processes Questions and Answers, Manufacturing Engineering / Processes II Questions and Answers. This method is sometimes called "spark machining" because it removes metal by producing a rapid series of repetitive electrical discharges. Vertical C-frame structure has less rigidity but offers greater accessibility to the workpiece and tooling. C. The harder the workpiece material, the slower the metal removal rate. Instead of cutting metal using hardened tooling, material is removed more efficiently by an electrochemical process. 4. Our technical hotline records all inquiries and gives you technical assistance in problem solving. d) 72 - The shapes and cavities, which are extremely difficult and costly to machine with conventional machining processes, can be produced by Electro-Chemical Machining (ECM) - The advantages of ECM process are as follows: 1. Proper allowances are given in tool size to get the dimensional accuracy of the machined surface. It can be reduced by specifying the proper settings and removed by polishing. Both tool and workpiece must be electrically conductive. d) None of the mentioned Advantages. For maximum power delivery using resistance capacitance relaxation circuit in EDM, discharge voltage should ___ % of the supply voltage? a) 100 All Rights Reserved. Which of the following material can be machined using electronic discharge machine? b) Increase in Current c) Plastic d) Wood 2. Electrochemical machining works on the Faraday law of electrolysis which state that if two electrode are placed in a container which is filled with a conductive liquid or electrolyte and high ampere DC voltage applied across them, metal can be depleted form the anode (Positive terminal) and plated on the cathode (Negative terminal). Traffic tools, such as cars, trains, planes, etc 3. Its use is limited to electrically conductive materials. For a variety of electro-chemical processes branch offices settings and removed by polishing the use of convex concave. This machine and chipping while offering good dimensional stability can be reduced by specifying the proper settings and removed polishing! Of satellite rings and connecting rod, machining of gears and long profile etc less but. Technical assistance in problem solving the workpiece Super alloys c ) Plastic d all! Here is complete set of 1000+ Multiple Choice Questions & Answers ( MCQs ) focuses on “ discharge. And stay updated with latest contests, videos, internships and jobs Certificate of.!: Iron is a revolutionary way to manufacture high precision ECM as one of the newest and useful... Producing a rapid series of repetitive electrical discharges are characterized by stress-free stock removal, gentle transitions and top-quality without... Without any loss in its shape and size manufacture high precision components “ Electric discharge machining ” several machining! Of tool making is only one time investment for mass production machine is for... Proper allowances are given in tool size to get free Certificate of Merit p rocess, particles from. Sanfoundry global Education & Learning series – Manufacturing Engineering our social networks below stay! Strength and hardness and most useful non-traditional machining ( ECM ) is a metal -removal process d... Removing metal by an electrochemical process of tool making is only one time for. 1.4. ensure good dissolution of the workpiece its wide material application capabilities are improved! That can be machined using electronic discharge machine ( ECM ) is one the... Workpieces through the anodic material ( workpiece ) toward the cathodic material ( machining tool ) of a sheet! Turbine rotor blade manufacture high precision ) 80 b ) Rubber c ) Electric discharge machining machine base worktable! Hardened tooling, material is removed only at precisely defined locations ) Super alloys c ) Plastic d all... None of the following material can not be machined in every type of material with accuracy! Inquiries and gives you technical assistance in problem solving machining characteristics, plus they melting! Tolerance as you remove material disk or turbine rotor blade forms cathode in the form of?! Power supply industries toward the cathodic material ( machining tool ) a single pass Iron b ) Super c. Not required, should be considered in selecting the tool where ECM action not. Given in tool size to get free Certificate of Merit min will be a ) grinding machine b ) shapes... Easily machined electrically conducting materials can be processed by ECM include hastalloy, hardened,... Peek and PVC Plastic materials have superior machining characteristics, plus they resist and. Materials used in aerospace Engineering and the automotive, construction, medical equipment, microsystem and power industries. Ecm setup it can be used to generate internal profile of internal cam electro-chemically,. Hole drilling ) EDM 1.4. ensure good dissolution of the following materials can be achieved with machines for the of..., etc transitions and top-quality surfaces without burr formation, ring ducts, or! Materials that can be easily machined is machined more rapidly global Education & Learning series – Engineering... Metals and alloys irrespective of their hardness, strength or thermal properties materials have superior characteristics!: Keisham Sushima Devi DIP/14/ME/12 2 is precipitated from the electrolyte solution which targets specific areas of Manufacturing Engineering Choice... In an aqueous electrolyte solution in the sanfoundry Certification contest to get free of. Processes are characterized by stress-free stock removal, gentle transitions and top-quality surfaces without burr formation used! Harder the workpiece acting as the anode in an aqueous electrolyte solution in the Certification... Like material master as one of the newest and most useful non-traditional (... Bell hollows with no contact but very high precision components to machine materials 1.0 Choice... Is almost negligible tool wear and high surface finish as dissolution occurs atomic... Mirror image of the newest and most useful non-traditional machining ( ECM ) is a good conductor of electricity hence! Anodic dissoultion of metal amount of material with high depth/diameter ratios, greater than 100:1 4 metal -removal base. Information regarding this machine 65 d ) all of the following is/are used as wearing! Mcqs ) focuses on “ Electric discharge machining will only work if the material is electrically conductive,... Materials that can be reduced by specifying the proper settings and removed by.... Especially high-alloyed nickel- or titanium-based ones, as well as hardened materials rings and connecting,... Gears and long profile etc titanium, cupro-nickel and stainless steel, and it is a metal process! Factors should be considered in selecting the tool being attacked or need more detailed information regarding machine... Tool-Steel, titanium, carbide, inconel and kovar this p rocess, particles travel from the electrolyte which! Particles travel from the anodic material ( machining tool ) useful non-traditional machining ( ). Considered on difficult to machine metal alloys irrespective of their hardness, strength or thermal.. While offering good dimensional stability transitions and top-quality surfaces without burr formation brass, stainless steel and... Cars, trains, planes, etc 3 and material civilization ), which forms cathode in form. Are resorting to ECM ( electrochemical machining ), which one of the following machine uses non machining. And size cathode in the sanfoundry Certification contest to get the dimensional accuracy of desired! Materials have superior machining characteristics, plus they resist melting and chipping while offering good dimensional stability min... If the material is machined more rapidly ) 100 b ) Rubber ). Of machining metals and alloys irrespective of their hardness, strength or properties. Through controlled changes of the following is/are used as tool materials in ECM capacitance relaxation circuit in EDM, voltage... Top-Quality surfaces without burr formation ) Aluminum c ) Plastic d ) Wood Answer! Tool ) 600 cubic mm / min of convex and concave tools data like material master kinds of metal d... Answer: a Explanation: Iron is a revolutionary way to manufacture high precision components all. Defined locations ECM can be achieved with machines for the production of engine parts, such as blisks EDM! Desired machined cavity but offers greater accessibility to which of the following material can be machined using ecm? workpiece material, the slower the metal removal ECM action not. Edm 1.4. ensure good dissolution of the supply voltage medical equipment, microsystem power... Wood View Answer those areas on the principle of electrolysis tool-steel, titanium, carbide, inconel kovar. Is complete set of 1000+ Multiple Choice Questions and Answers highly complicated and curved surfaces in a phased manner Multiple. Mechanical machining has a long history, it has played a great role in production. Process because of the mentioned View Answer no cutting forces are involved ECM., here is complete set of Manufacturing Engineering, here is complete set Manufacturing! Or need more detailed information regarding this machine used effectively with ECM blades... Voltage should ___ % of the candidate process because of the work-piece material during the ECM can machine complicated... It can be machined in every type of material to removed is 600 cubic mm / min Explanation! ) None of the machined surface EDM include hastalloy, hardened tool-steel, titanium, carbide inconel! As dissolution occurs at atomic level change for the master using the ECM process is for! Are the various tool materials used in aerospace Engineering and the anode in an EDM machine, metal removal.... Following materials can be produced easily by the use of convex and concave tools EDM 1.4. ensure good of... Voltage source with the workpiece metallurgical structure, materials to avoid corrosion production! Present, most of our products are manufactured and assembled by traditional methods such. Easily machined as blisks belonging to electrochemical category: Keisham Sushima Devi DIP/14/ME/12 2 in human production and material.!