机电工程专业英语 教学课件 作者 马佐贤 主编 张雪娟 副主编 Unit 6.pptVIP

尚辅网 尚辅网 Assignment * * 尚辅网 Unit 6 Properties of Materials Dialogue 6.1 Properties of Materials 6.2 尚辅网 尚辅网 Dialogue 6.1 Welcome to our factory! 尚辅网 In what area is basic stretch forming mainly used? Basic industrial stretch forming is used mainly in the aircraft industry ? 尚辅网 what are advantages of stretch draw forming? The advantages of this process are the lack of spring-back in the finished part, the utilization of a single action press, 尚辅网 What is the classical disadvantage? Stretch draw forming is applied only to certain panel designs. 尚辅网 Properties of Materials 6.2 尚辅网 What are the physical properties of a material?? 尚辅网 The physical properties of a material color，density，specific heat，coefficient of thermal expansion，thermal and electrical conductivity，magnetic properties，and melting point． 尚辅网 machine tool 机床 What are the mechanical properties of a material? 尚辅网 Mechanical properties fall into five broad categories： 1.Strength 2. Hardness 3. Elasticity 4. Ductility 5. Toughness 尚辅网 (1)Strength is the ability of a material to resist penetration and abrasion． (2)Hardness is the ability of a material to resist penetration and abrasion． 尚辅网 machine tool 机床 (3)Elasticity is the ability to spring back to original shape． (4)Ductility is the ability to undergo permanent changes of shape without rupturing． 尚辅网 machine tool 机床 (5)Toughness is the ability to absorb mechanically applied energy． *