• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
• Level: GCSE
• Subject: Maths
• Word count: 1646

# Rolling and annealing of copper block.

Extracts from this document...

Introduction

Title:Rolling and annealing of copper block.

Abstract:

The hardness of a soft copper block was tested at City University, of increasing lengths and decreasing thickness after undergoing cold rolling. After the maximum length was obtained the copper a cut section was annealed to different temperatures. From the experiment it was found that as the block got thinner and longer the hardness increased. The experiment also shows that when the long copper section was annealed as the temperature was increased the breaking or tensile stress decreased.

Introduction:

The purpose of this Lab exercise is to investigate the effects of cold working and of annealing on the crystal structure and the hardness of a sample of copper (dimensioned at 50x25x5mm). The experiment is designed to allow us to see first hand the changes that take place in the material as it is subjected to varying degrees of work (deformation) and heat treatment.

Cold working uses the concept of “strain hardening”, to “temper” the metal, which is based on increasing the dislocation density within the material.  These dislocations are misalignments of atoms in the crystal lattice

Middle

19.80

40.12

64.07

76.26

89.09

The percentage increase in length:

1. Measure the lengths of the original block and the rolled block.
2. Subtract the rolled length from the original length and then divide it by the original length.
3. This will give the percentage increase in length when multiplied by 100.

Table 2: % increases in length, for given length.

 Length (mm) 51 56 65 86 146 224 470 % Increase in length 0 9.8 27.5 68.6 186.3 339.2 821.6

The Hounsfield Tensometer test is then carried out on the final sample that has been cut, two of which are annealed and another remained as rolled and no heat treatment.

When the Hounsfield Tensometer test is carried out the Maximum load is given from which you have to calculate the tensile strength with equation (1) and (2).

Table 3: Annealing temperature and tensile Strength

 Annealing temperature (oC) 0 160 360 Tensile strength (N/mm) 490.3 476.2 246.7

The data is analysed by plotting three graphs, % reduction in area against

Hardness, % increases in Length against hardness and Tensile strength Vs Annealing temperature.

The plot of data is shown in fig 1, fig 2 and fig 3.

Discussions:

From the graph of data shown in fig.1, it can be seen that the points are increasing consecutively until the maximum hardness is approached after this point the graph has an exponential affect.

Conclusion

Relationship between Annealing and Hardness

The above plot also shows that samples #1 and #2 had similar hardness, and hence, crystal states.

Note: after several passes, one group’s 60% sample was erroneously passed through the rollers transverse to the direction of the initial passes.  This caused a general cupping of the sample and subsequently brittle fractures occurred.  The effect on the sample is unclear, but it is likely that it has a different deformation of its crystal structure compared to the other two samples, which were rolled in the same orientation each time.

Hardness Testing:

Each group performed hardness tests using Rockwell Hardness Testers (by Wilson) in the Polishing Lab in Meuller Hall.  Hardness is a measure of a material’s resistance to deformation by surface indentation or abrasion.  According to the Callister text, the Rockwell Hardness tester works by pressing 1/16 inch steel ball under an initial minor load of 10kg into the sample, followed by a second major load on 100kg (B scale) into the test sample and comparing the depth of the indentation made by each load to derive a relative number indicating the “hardness”.   Multiple readings are taken at various locations on each sample, which are then averaged to find and average hardness number for the specimen.

Figure 1.

Figure 2.

Figure 3.

Appendix:

Raw data showing intermediate calculations:

This student written piece of work is one of many that can be found in our GCSE Comparing length of words in newspapers section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related GCSE Comparing length of words in newspapers essays

1. ## The aim of this experiment is to test the trainer for is suitability for ...

testing the strength of the trainer to tell us how strong it is, this will tell us about how long the trainer will probably last. Method 1. Firstly I cut off a piece of the lace. 2. Then I put the G clamp on the side of the science table and tied the lace to the G clamp.

2. ## An Experiment to measure the gravitational field strength of the Earth and the length ...

I am having a minimum length of 0.300m. For smaller lengths, the pendulum would oscillate more rapidly there would therefore be a smaller time period. This would subsequently be harder to observe and record meaning more human errors would be expected.

1. ## Statistically comparing books

It will also help me find the upper and lower quartiles so then I will be able to find the Inter-quartile range. I will find the Standard deviation too as I will be able to see the spread of the data.

2. ## Investigating the Levels of Processing Theory

I will make sure that the conditions of the experiment are controlled, by ensuring all participants take part on their own so there is no influence from other people. I will time the first part of the experiment (the rating of the words)

1. ## Investigation into the effects of levels of processing.

This suggested that rehearsal may not have been necessary in order to remember words, but meaning may have been more important. Aims and Hypotheses The aim of this investigation is to find out if information that is deeply processed is better remembered than information that is shallowly processed, as suggested by the Levels of Processing Model.

2. ## Investigate if there is a relationship between the length and width of the leaves.

Grouped frequency table for width. Width mm Tally Frequency (f) Mid-point (x) f*x fx� 20-29 / 1 24.5 24.5 600.25 30-39 //// 5 34.5 172.5 5951.25 40-49 //// //// /// 13 44.5 578.5 25743.25 50-59 //// /// 8 54.5 436 23762 60-69 //// / 6 64.5 387 24961.5 70-79 // 2 74.5 149 11100.5 TOTAL

1. ## Does people's ability to estimate lengths improve after being shown an accurate length?

As would the length 105mm be calculated to have a difference of 10mm. Once all the results have been entered and the differences calculated, I will then begin to produce various statistical graphs to show my results graphically examples include cumulative frequency graphs, box plots and scatter graphs.

2. ## Find out the correlation between organization of material encoded and its retrieval.

Therefore, their education level should have no large differences. * Subject effect is also one of the extraneous variables. The first one is the demand characteristics. If the subject are informed the purpose of this experiment, they will try to be cooperative and conform the hypothesis by writing down less words in the group that got the unorganized data.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to