机械加工1（Machining 1）.doc

机械加工1（Machining 1） Review of mechanical fundamentals 1. mechanical properties of metal materials. What do physical properties contain? (P1) Answer: mechanical properties: strength, plasticity, hardness, toughness and fatigue resistance Physical properties: the performance of materials subjected to the effects of light, gravity, temperature, power plants, and magnetic fields is known as physical properties, including electrical properties, magnetic properties, optical properties, density, and melting point of materials. The relationship between the work stress of 2. parts in use and the yield strength and the conditional yield strength? (P3) Answer: the larger the 6S, the stronger its resistance to plastic deformation, the less likely to occur plastic deformation. The stress produced when the specimen produces 0.2% residual deformation is used as the yield limit of the condition. 3. carbon steel and cast steel is defined? (P31) Answer: the alloy with carbon content of 0.0218%~2.11% is called carbon. 4. cutting parameters three elements and their definitions, units? (P113-114) Answer: cutting speed Vc, feed rate, cutting depth is f AP 5. what is the difference between rough machining and finishing? What is the selection principle of roughing cutting parameters? (P115) Answer: rough, cut and feed quantity is generally used in the larger, the cutting speed is not very high. The finishing time, often using small to be cut and feed rate, cutting speed is high. 6. what are the two wiring methods used for DC power supply, and what are they used for? (P82) Answer: positive method: used for high melting point, larger size welding parts welding, Negative connection: used for thin, non-ferrous metals, stainless steel and cast iron. 7. what are the main points of turning and milling? (P132.137) Answer: turning is mainly used for turning surfaces, Milling can process a variety of flat, groove, gear parts, spiral surface and special curved surface. 8. what is called progressive mi