Unformatted text preview: Circle the types of materials that exhibit a ductile to brittle transition temperature (DBTT) in the impact energy absorbed versus temperature diagram. Low Strength BCC metals High Strength alloys Thermoplastics FCC metals (1 point each) Circle the microstructural conditions that decrease the yield strength of a metallic material. Large grain size Low dislocation density Increasing the percentage of subsitutional alloy elements (1 point) Which materials property is directly related to the yield stress in metals? Critical resolved shear stress Modulus of Elasticity Fracture Toughness (4 points) The fracture toughness of a low-alloy steel (4340) at room temperature is 60.4 MPa √ m. It the material has a surface crack of 2.30 mm in length (a = 2.30 mm), what is the maximum load (N) that a sample with a cross-sectional area of A o =50.0 mm 2 can support before catastrophic failure? (Assume Y = 1.78) K IC = σ Y √π a a) 12.6 b) 400 c) 632 d) 20,000...
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- Spring '07
- increase decrease decrease, FRACTURE Brittle fracture, decrease decrease decrease