1. A material is said to be allotropic, if it has 2. a-iron in (Fe-C) system has a -------- crystal structure. 3. Pearlite is a combination of -- 4. ---- in crystalline solids can be classified as a bulk defects. 5. As a result of strain hardening mechanism become more brittle. but that meant material 6. The driving force for recrystallization is

Plastics may exhibit a change in properties as they age, particularly when subjected to elevated temperatures. Material properties such as tensile strength will increase with an increasing temperature as a function of increasing time. True or false.

Are nails are considered as direct materials.    True False Can be true, can be false

The properties of materials can be classified into the following categories: Mechanical Physical Thermal Electrical Magnetic Describe each category, include two specific properties in the description and say why those properties are of interest to a design engineer.

Distinguish between the upper yield point and the lower yield point?

Metal working Fe-C: What are possible sources of error in trying to obtain a specific hardness or strength?

A cylindrical rod 100 mm long and having a diameter of 10.0 mm is to be deformed using a tensile load of 27,500O N. It must not experience either plastic deformation or a diameter reduction of more than 7.5x103 mm. Of the materials listed as follows, which are possible candidates? Justify your choice(s). Material Modulus of Elasticity(GPa) Yield Strength (MPa) Poisson's Ratio Aluminum alloy 70 200 0.33 Brass alloy 101 300 0.34 Steel alloy 207 400 0.30 Titanium alloy 107 650 0.34 Part 1 What is the stress in MPa in the cylindrical rod? i MPa

Which of the following conditions/factors will reduce a materials fatigue resistance: Select one or more: a. Roughening or etching the surface b. Experiencing a permanent residual compressive stress c. Increasing the stress amplitude d. Experiencing a mean tensile stress e. Mechanically hardening the surface