The Effect of Metals and Alloys Annealed and Non-annealed and Their Resistance to Fatigue
Since 1934, more than 306 fatal accidents occurred because of metal fatigue. Problems like these are unavoidable, however, any way to prolong materials’ resistance to them are needed. This study involves various metals being annealed and then bent to determine whether or not the annealed metal lasts more bends than the not annealed ones. It was hypothesized that the annealed metals would last more bends before fracture than their non-annealed counterparts. Six different samples of 3 different materials will be used: bronze, aluminum, and copper wires (annealed to 500˚ F and non-annealed). Each one was taken and bent at a 90˚ angle in one direction, then in the other until the piece broke into 2 pieces. This cycle was repeated until all 24 were tested. The independent variable was whether the material was annealed or not, the dependent being the number of times the sample was bended before breaking. Although more testing will be necessary. The hypothesis was supported by the data collected, as all the annealed metals lasted more bends than that of the metals not annealed. It is now confident that annealing does have a positive effect on metals’ resistance to fatigue. However, this experiment was harder to perform than originally thought, as the first trial’s samples were incorrectly bent, forcing me to have to discard them and have 1 less trial. If this technique of annealing was applied to anything that is under constant stress such as planes, boats, buildings, etc. then they would potentially last longer saving materials and time in the future. It would save lives too for the people unfortunate enough to get trapped within one of these damaged structures. Although this is one step into improving metals resistance to fracture and overall durability, it is more than likely that this could play a part in a future experiment to further improve this further. Ben Staniewicz Period 6 2 Abstract
Annealing is the process of heating a material to high temperatures and then cooling. It aligns the structure, adding malleability and flexibility. Ben Staniewicz Period 6 3 What does annealing metals or alloys do? What is fatigue?
Fatigue is a fracture that occurs due to cyclic loading on a material.
What is an alloy? An alloy is a solid solution of multiple elements What is malleability? The extent to which solid materials may be deformed. What is load? The forces applied to a structure.
306 aircraft since 1934 suffered fatal accidents due to metal fatigue Of the 2700 liberty ships built in WWII, 400 were found to have been fatigued Buildings and any other metal-built structures are at risk Ben Staniewicz Period 6 4 Background
To find better ways to prevent catastrophic failure such as previously mentioned Save lives and money for future damage Ben Staniewicz Period 6 5 Purpose
If metals and alloys are annealed and their malleability is increased, would that improve their resistance to fatigue? When metals and alloys are annealed, it would take a longer amount of times and more load being put on it before it would fracture. Ben Staniewicz Period 6 6 Hypothesis/Problem Statement
Independent- The different metals or alloys being used, annealed and non-annealed and different metals/alloys. Dependent-Number of loads put on before fracture occurs Controls-All non-annealed metals and alloys Constants- Temperatures at which metals are annealed (500 ˚F, load put on each material (same measure each is bent), same size and shape of every material Ben Staniewicz Period 6 7 Variables
Bend each of the metals and alloys at a 90˚ angle then set straight to 180˚ and repeated Do this for each material of both the annealed and non-annealed counterpart Repeat for each sample (Aluminum, copper, and bronze) For each set of alloys and metals, repeat for a total of 3 times Ben Staniewicz Period 6 8 Procedure
Data correctly taken and immediately recorded Multiple trials were performed, to ensure validity Easily reproducible It is possible that there was error because it was not entirely controlled Ben Staniewicz Period 6 11 Conduct of Study
Samples may not have been bent at 90˚ exact, putting more pressure on 1 piece than another Certain metals were harder to bend than others, requiring more force to be put on them, further straying results Ben Staniewicz Period 6 12 Errors
Ensure that metals/alloys are bent to 90˚ This would be done easily by using a piece of machinery to bend each one Have different and more metals in this experiment This could be done by making more metals participate, hopefully with closer malleability to eachother Ben Staniewicz Period 6 13 Recommendations to prove errors
Data does seem to support hypothesis All annealed materials lasted more bends than the non annealed ones. Aluminum: 28, 26, and 27 bends before fracture. Annealed, it withstood 35, 36 and 35 bends before fracture. Copper: 38, 39 ,40 bends before fracture Annealed, it withstood 45, 44 ,and 46 bends Ben Staniewicz Period 6 14 Results
As technology progresses and as the advancements put in place by this experiment are used, there will be far less metal fatigue. Although it is unavoidable, this will drastically reduce the amount of failure from this. This will, in turn, save countless sums of money, save people from the frustration of this happening (and the extra work to replace it), and possibly even save lives in the process. Ben Staniewicz Period 6 15 Future
This shows that annealing does improve the metal’s resistance to fatigue With further testing to further prove it, it can be applied to those technologies which although costing more short-term, long-term costs will be saved Ben Staniewicz Period 6 16 Signifigance
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