How does aging temperature affect the time and hardness

Assignment Help Electrical Engineering
Reference no: EM131069745

Objective: To study the time and temperature variations in the hardness of Al-4% Cu alloy on isothermal aging.

Introduction

Materials can be hardened by inhibiting the motion of crystal defects called dislocations. In pure metals, the presence of defects (such as vacancies, interstitials, dislocations and grain boundaries) can enhance the strength. In single phase alloys, additional resistance to deformation may arise from the presence of foreign atoms. In two-phase alloys, additional stress is needed to enable the dislocation to intersect the  second-phase particles. A finely dispersed precipitate may, therefore, strengthen the material. This phenomenon is termed precipitation hardening.

Procedures

1. Stamp the five 2024 Al specimens with an identifying mark.

2. Measure the hardness of all of the specimens using Rockwell B.

3. Place all five in a heat-treatment crucible and into a furnace for solution treatment at 500°C (930°F) for 30 minutes.

4. Natural Aging - Remove one specimen and drop into a pail of water. Once the specimen is cool, measure the Rockwell B hardness at intervals of approximately 30 min, 90 min, 1 day, and 1 week for this specimen. It will be necessary for one member to come back to the lab during the week when the lab is in session to measure the hardness.

5. Artificial Aging - Remove the remaining four specimens and drop them into a pail of water. Once the specimens are cool remove them from the quenching bucket. Measure the Rockwell B hardness. Next, transfer the specimens to a furnace set at 190°C (370°F).

Remove one sample after 3 min, 10 min, 60 min and 90 min. Quench into water and measure the Rockwell B hardness. After one week, again measure the Rockwell B hardness of the 3- and 10-minute artificially aged specimens.

Write Up

1. Prepare a memo report.

2. Plot the hardness vs. time of aging for each aging temperature, using Excel.

3. How does aging temperature affect the time and hardness?

4. What happens to the 190°C (370°F) 3 and 10 minute specimens after one week? Why?

5. If you were going to use 2024 Al in an application at a temperature of 190°C (370°F), what problems could be encountered?

6. Discuss errors in this experiment and their sources.

Attachment:- assign.rar

Reference no: EM131069745

Questions Cloud

Psychological contract expectations of your boss : What are your psychological contract expectations of your boss and coworkers? Give examples of conflicts you have had at work, listing the expectation that was not met.
Find a hospital in your area : Go to www.jointcommission.org. Click on Quality Check and find a hospital in your area. View the accreditation quality report. Describe what you have learned about this hospital. How could health care consumers use this site in deciding where to s..
Discuss the beneficial or detrimental effects : Discuss the beneficial or detrimental effects of the overloads on the fatigue life
Next performance improvement project : Describe where this hospital needs the most improvement and why. Describe what you think the most important opportunity for improvement is. Recommend where to focus the next performance improvement project.
How does aging temperature affect the time and hardness : How does aging temperature affect the time and hardness? What happens to the 190°C (370°F) 3 and 10 minute specimens after one week? Why?
Distance of total crack growth under constant amplitude : The fatigue crack is propagated ahead of a stress concentration under a constant amplitude of imposed cyclic compressive loads. The cracks arrest naturally after advancing a distance of ten times the notch-tip radius. At this point, the notched sp..
Discuss the different types of advance directives : Discuss the different types of advance directives and the pros and cons of each. Do you have an advance directive? Has what you have learned this unit caused you to consider the need for one? Why or why not?
Delegation at boyne usa resorts : Detroit native Everett Kircher moved to northern Michigan in 1947 and purchased land (for the price of $1) necessary to start his first ski resort known today as Boyne Mountain. Kircher practiced a traditional chain of command in a vertical organi..
Risk of using a signed public key : Describe a scenario where the risk of having an unsigned public key is not acceptable but the risk of having a signed public key is acceptable. Describe a scenario where risk of using a signed public key is not acceptable

Reviews

Write a Review

 

Electrical Engineering Questions & Answers

  Problem regarding the transformation example

Balanced 3-φ system with the line voltage of 866 V, the frequency of 60 Hz, and with Y - connected source feeds ?-connected load with the impendence of 174 - j249 Ω. Line impedance is 2 + j3 Ω and phase sequence is positive.

  Calculate the thevenin equivalent impedance zth

1) Calculate the open circuit voltage VOC (ZL removed) (magnitude and phase angle) 2) Calculate the Thevenin Equivalent impedance ZTH for this circuit (magnitude and phase angle)

  Wireless home ac remote

For each of the following application: A) Wireless home AC remote.B) Nuclear Power plant monitoring system.

  What is the input resistance of the resulting current divide

A designer searches for a simple circuit to provide one-third of a signal current I to a load resistance R. Suggest a solution using one resistor. What must its value be. What is the input resistance of the resulting current divide

  Find a minimal sum-of-products expression for each function

with karnaugh maps, find a minimal sum-of-products expressionfor each of the following logic functions. Indicate thedistinguished 1-cells in each map a) F = ΣA,B,C,D (1,4, 5, 6,11, 12,13,14,15) b) F = ΣA,B,C,D (0, 1, 2,5, 8, 9,10, 11,12)

  How to calculate critical resistance

How to calculate critical resistance?

  Find the pole frequency fc for the fourth pole

A certain amplifier has pole frequencies of f1=f2=f3=50MHz. The DC open-loop gain is 10^5. Find the pole frequency fc for the fourth pole so that the phase margin is 30 degrees for beta = 0.1 Also, find the corresponding gain margin.

  Compute the battery life in years and months

An embedded system consumes the following current when in different operating modes: Operating Mode Avg. Current Time Data Acquisition 4.2 mA 1.8 ms Communication 22.6 mA 2.5 ms Sleep Mode 0.5A 5 hours

  Determine the values of the equalized output pulses

The result of transmitting a single pulse through a channel is a received sequence of pulses at the sampling instants given by {0.1, 0.3, -0.2, 0.96, 0.4, -0.1, 0.1} where the leftmost sample is the earliest. The value 0.96 corresponds to the main..

  The transfer function of the first order system

The transfer function of the first order system is: H1=1/ST+1

  Determine what is the initial energy in the capacitor

Voltage across a .1 micro farad capacitor is : v(t)=25v when t is less than or equal to 0; and v(t)=(Bte^-1000t) + (C(e^-1000)v) when t is greater than or equal to 0 Initial current is 100mA A) what is the initial energy in the capacitor

  Design a circuit that provides a voltage gain of 3

Design a circuit that provides a voltage gain of + 3. Draw the circuit schematic identifying supply voltages and show your work on component selection.

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd