Materials design and selection Knowledge-Based Practice

Questions

1. 1.

   In the materials selection and design for a solid electrolyte in solid-state lithium batteries, which set of functional properties is primarily required to enable high cell efficiency and prevent internal short circuits?

   • A) High ionic conductivity, negligible electronic conductivity, and a wide electrochemical stability window
   • B) High electronic conductivity, low ionic conductivity, and high chemical reactivity toward lithium metal
   • C) High electronic conductivity, negligible ionic conductivity, and high interfacial resistance
   • D) Low ionic conductivity, moderate electronic conductivity, and a narrow electrochemical stability window
2. 2.

   In the materials selection process for permanent load-bearing orthopedic implants, which combination of properties is primarily required to prevent bone resorption caused by stress shielding while maintaining implant longevity?

   • A) High Young's modulus, low fatigue strength, and high chemical reactivity
   • B) Low elastic modulus matching cortical bone, high yield strength, and excellent biocompatibility
   • C) Extremely high stiffness, low fracture toughness, and rapid bioresorbable degradation
   • D) High thermal expansion coefficient, low yield strength, and passive oxide breakdown
3. 3.

   In the design and selection of materials for thermal barrier coatings applied to nickel-base superalloy turbine blades, which combination of functional properties dictates the selection of the ceramic top coat?

   • A) High thermal conductivity, low thermal expansion coefficient, and high chemical reactivity with combustion gases
   • B) Low thermal conductivity, high melting temperature, and a coefficient of thermal expansion closely matching the underlying metallic bond coat
   • C) High electrical conductivity, low fracture toughness, and complete absence of microstructural porosity
   • D) High mechanical ductility, rapid oxygen diffusivity, and a thermal expansion coefficient far lower than that of the superalloy substrate
4. 4.

   In the materials selection process for structural ceramic components exposed to sudden temperature changes, which combination of material properties must be maximized to minimize susceptibility to thermal shock cracking?

   • A) High thermal expansion coefficient and high Young's modulus with low fracture strength
   • B) Low thermal conductivity and high thermal expansion coefficient with high density
   • C) High fracture strength coupled with low thermal expansion coefficient and low Young's modulus
   • D) High electrical resistivity and low fracture toughness with high heat capacity
5. 5.

   In materials selection for structural applications, which material performance index must be maximized to minimize the mass of a beam of specified length and square cross-section under a defined bending stiffness constraint?

   • A) $\frac{E}{\rho}$
   • B) $\frac{E^{1/2}}{\rho}$
   • C) $\frac{E^{1/3}}{\rho}$
   • D) $\frac{\sigma_y^{2/3}}{\rho}$

Answers and step-by-step solutions appear after you finish the test.