Title: Summary Part Machining

Choose the correct statement.

- Machining processes are often necessary to impart the desired dimensional accuracy, geometric features and surface finish of parts produced by other processes. Additionally, machining is often employed for complex shapes that cannot be produced economically using other shaping techniques. (correct)
- Machining processes are solely used to impart the desired dimensional accuracy, geometric features and surface finish of parts produced by other processes.

- Machining generally takes more time, wastes some material, has no positive effect on the bulk properties of the workpiece, and may have adverse effects on surfaces produced. (correct)
- Although machining is as fast as other processes, it wastes some material, has negative effects on the bulk properties of the workpiece, and may have adverse effects on surfaces produced.

- Metal parts to be machined may have been produced by casting, forging, extrusion, or powder metallurgy. The closer this blank to the final shape desired (near-net shape), the fewer the number and extent of the subsequent machining processes required. (correct)
- Metal parts to be machined may have been produced by casting, forging, extrusion, or powder metallurgy. The simpler the shape of this blank (for example a slab, a cube or a rod), the easier the machining and the fewer the number and extent of the subsequent machining processes required.

- Some variables that determine the outcome of the cutting process are tool shape, the depth of the cut, and the cutting speed. Cutting tools are characterized by their rake and clearance angle. (correct)
- Some variables that determine the outcome of the cutting process are tool shape, the total cutting time, and the cutting speed. Cutting tools are characterized by their rake and flank angle.

- Cutting processes remove material from the workpiece by producing chips. Continuous chips produce good surface finish. In contrast, built-up edge adversely affects surface finish. (correct)
- Cutting removes material from the workpiece by wear processes. Continuous wear (the tool in continuous contact with the workpiece) produces good surface finish. In contrast, discontinuous wear adversely affects surface finish.

- Cutting forces increase with cut depth, material hardness, friction coefficient, feed rate, and inversely with the rake angle. (correct)
- Cutting forces increase with cut depth, material hardness, friction coefficient, feed rate, and the rake angle.

- In rough machining, the surface finish is of no importance, as the main goal is to remove a large amount of material at a high rate. In finish machining, it is important to consider the surface finish to be porduced. (correct)
- In both, rough and finish mashining, the surface finish is important to consider.

- Temperature rise in machining is an important consideration, since it can have adverse effects on tool life and the surface integrity of the machined part. (correct)
- Temperature rise in machining is an important feature of machining, since it softens the workpiece material and hence facilitates machining – hence, the higher the temperature at the tool, the better the outcome.

- The main purposes of cutting fluids are: Reduce friction and wear, thus improving the tool life and surface finish of the workpiece. Cool the cutting zone, thus improving tool life and reducing the temperature and thermal distortion of the workpiece. Hence, cutting fluids are coolants and / or lubricants. (correct)
- The main purposes of cutting fluids are: Cleansing of the workpiece from dirt and produced chips hence improving the surface finish of the workpiece. Cool the cutting zone, thus improving tool life and reducing the temperature and thermal distortion of the workpiece. Hence, cutting fluids are solvents and / or lubricants.

- Tool wear depends on workpiece and tool material, cutting speed, feed, depth of cut, and cutting fluids. (correct)
- The tool material is the factor influencing tool wear.

- Machinability generally is defined in terms of surface finish, tool life, force and power requirements, and chip control. The machinability of materials depends on their composition, properties and microstructure. In general, metals, polymers and ceramics can be machined with the propert tools and process conditions. (correct)
- Machinability generally is defined in terms of surface finish, tool life, force and power requirements, and chip control. The machinability of materials depends on their composition, properties and microstructure.  In general, only metals can be machined.

- Turning is a machining process that typically produces axisymetric parts with external and internal circular cross-sections. (correct)
- Turning is a machining process that typically produces parts with external and internal cross-sections of arbitrary shape: circular, square or any other shape is accessible.

- Milling is one of the most common machining processes, because it is capable of economically producing a variety of shapes and sizes from a large number of workpiece materials. Most of the milling processes use multitooth cutters and tools at various axes with respect to the workpiece. (correct)
- Milling is one of the most common machining processes, because it is capable of economically producing a variety of shapes and sizes from a large number of workpiece materials. Most of the milling processes use multiple cutting tools simultaneously and tools at various axes with respect to the workpiece.

- Machine tools used to produce complex shapes are mostly computer controlled. Computer-controlled machines are called CNC machines, which refers to "computer numerical controlled" machines. (correct)
- Machine tools used to produce complex shapes are sometimes computer controlled. Computer-controlled machines are called CNC machines, which refers to "computer numerical controlled" machines.

- Because the are versatile and capable of combining multiple machining operations, machining centers are now among the most imporant machine tools. They combine drills, lathes and milling machines in a single tool. (correct)
- Because the are versatile and capable of combining multiple machining operations, machining centers are now among the most imporant machine tools. They combine machining (milling, drilling etc.) and forming capabilities (sheet-metal forming, forging) in a single tool.

- Optimum cutting speeds can be determined for both minimum machining time per piece and minimum machining cost per piece. (correct)
- Optimum cutting speeds can are determined for minimum machining time per piece, which always corresponds to minimum machining cost per piece.

- Advanced machining processes have unique capabilities, utilizing chemical, electrochemical, electrical, and high-energy-beam sources of energy. Their main advantage is that the mechanical properties of the workpiece material are not significant, because these processes rely on mechanism that do not involve the strength, ductility, or toughness of the material; rather, they involve physical, chemical and electrical properties. (correct)
- Advanced machining processes have unique capabilities, utilizing chemical, electrochemical, electrical, and high-energy-beam sources of energy. Their main advantage is that mechanical properties of the workpiece material for good machinability are opposite of those in traditional machining: materials to be cut need to be hard and brittle. Hence, advanced methods are an ideal complement to traditional methods

- Chemical methods and electrocal methods of machining are suitable particularly for hard materials. They do not produce forces, significant temperatures or residual stresses. However, they often require electrical conductivity of the workpiece. (correct)
- Chemical methods and electrocal methods of machining are suitable particularly for hard materials. They do not produce forces, significant temperatures or residual stresses. They can be used to machine all materials.

- Laser beam machining possesses a high flexibility of operation with robotic controls, and is economically competitive with various other processes. As in all high-energy-beam methods, the heat input and the heat affected zone in the material must be considered. (correct)
- Laser beam machining possesses a low flexibility of operation and is only used to cut 2D sheets. Yet, it is economically competitive with various other processes. As in all high-energy-beam methods, the heat input and the heat affected zone in the material must be considered.

- Water-jet machining of soft materials can be performed with water only, while the cutting of hard materials requires the use of abrasive particles mixed into the water jet. (correct)
- Water-jet machining of all materials solely relies on a high-velocity jet of pure water.