Material Failure Analysis

Material Failure abridgmentQuestion 1) in that location argon axles on all vehicles much(prenominal) as cars as the axle supports the hertzs parallel to the opposing wheel whilst championing the balance of the remains of the car. It in addition transmits torque from the axle to the wheels to give it power that is efficient in the motility of the car. Other vehicles such as heavy-duty trucks will non fool a shaft like the front beam axle on that vertexfore it serves whole as a suspension and steering component. (Vehicle Axle, 2017)It is likely that the produce wheel axle was failed by fag out as this is very(prenominal) common. The axle must be equal to carry the charge of the vehicle and any cargo that has been loaded. This is ordinarily enjoin at heavier vehicles such as moneymaking(prenominal) vehicles that carry around goods. all all over clock age the axle could erosion down if excess stress is applied to the axle. This is called a high-cycle fatigue wh ich toilet be shown by an S-N wave otherwise know as the Wohler curve. August Wohler was a German rail direction engineer, best remembered for his overbearing investigations of metal fatigue. (August Wohler, 2016) As we stinker forgather from Figure 1, this is a Wohler curve example for brittle aluminium that shows when you retain stress over the eventual(prenominal) Tensile Strength (UTS), the life reduces over time and wears out and would cut in which relates to if stress above the UTS is applied on the rear axle it could in like manner hold in to it breaking.When too much stress (more than what the recommended axle capacity) is applied to the vehicle, the axle begins to form small injurys eroding down the structural integrity over time. Stress on the rear axle could also be applied from things such as driving in harsh conditions like bumpy roads or potholes. other very common priming coat (especially older vehicles) if the vehicle does not look at the worthy maint enance that could trauma the vehicle over time from separate such as shafts, gears, components of the axle or rusted parts that progress to not been c ard for. (How do you break an axle?, 2017) These therefore could potentially lead to the axle breaking by fatigue over time.The way we pot psychoanalyse if the rear axle was unconnected on impact is by using a mode called fractography. Fractography is a order that is utilize to determine the cause of failure of engineering expressions. (Fractography, 2017) For actual science, fractography is employ to check crack growth behaviour. The method used for this is carried out by using an optical microscopy ( participate 2) with angled lighting on the broken axle to get hold upon out the degree of piece of cake and possibly the origins. This process is enough to p obligate the cause of the cracking and the growth number. Common reasons that could cause the material to crack are contaminations, stress concentrations and so on In conclusion numerous factors can separate if the rear axle breaking was caused by fatigue failure or failure on impact. It could vary for reasons such as if the vehicle had been carrying a heavy load over time for example a commercial vehicle that carries goods that is heavier than the Ultimate Tensile Strength (UTS) of what the axle can hold. Proven by the Wohler curve over time the life cycle of the axle will wear down and eventually break. For vehicles that do not carry loads that apply excess stress on the rear axle, the reasoning of the axle breaking could be from natural causes from the environment such as speeding over potholes, parts rusting or no p roundr maintenance on the vehicle could lead to the structural integrity breaking down over time causing it to be in an accident. By using fractography on the broken axle could show leads to why the accident was caused by looking at the cracks and the pattern of the spread to see if it was caused by load or not.Question 2)A o cclusion is used to lift heavy loads or to multifariousness the direction of business leaders applied. It consists of a wheel with grooves on an axle that can be compulsive with pulley systems like electrify roundabout, c fitting, chain etc. These pulleys can snuff it using applied human force to lift heavy objects. The reason why humans can lift heavy objects with the pulley is because the pulley system such as fit out traffic circle transmits the tension force around the pulley allowing humans use no effort because there is no energy loss because of the friction. nonetheless for much heavier items that humans cannot lift, machinery is used such as cranes. If the pulley system does not dissipate or store energy, then its mechanical advantage is the number of parts of the round that act on the load (Pulley Systems, 2017).Wire gets are usually make from a non-alloy light speed make with a very low carbon content of 0.4 to 0.95%. (Carbon steel rope, 2017) This allows the rope to fuck send off an extremely high speciality that can hold large tensile forces and be able to black market sheaves (pulley with a groove) with some(prenominal)what small diameters. If no chemical/mechanical footing, ebullient heat or corrosion is involved in the equip rope failing then the rope will fail in the sphere which has been exposed to the highest core of detrition and fatigue. This means that the likeliest sector that the wire rope failure will occur can be predicted. Wire ropes also vary from different aspects such as the number of outer strands and the size of it of the core. For example if you had less outer strands, the core would not be able to hold the load that the outer strands will hold it instead. On the other hand, if you had more strands, the core would be bigger therefore it would hold the load however the outer strands become loose over time but that would not make the rope fail. oneness way the wire rope could have failed is the end of the rope wearing out over time in a Flemish eye and could potentially come apart causing it to fail due to the load exceeding the weight limit of the bond between the Flemish eye and the wire rope. There are many ways that the wire rope can be terminated to prevent and stop this from happening. These include methods such as thimbles, clamps, sockets etc. with termination efficiencies that range from 70-100%. However there are also cons with some termination methods such as thimbles. There is the risk that when the wire rope is terminated, it could crouch too tightly especially when the loop is connected to a device that concentrates the load on a relatively small area.(Wire rope bend, 2017) The wire ropes need to have a squiffy structure requiring it to have been stressed by things such as wear and corrosion. It also call for to be inspected using a magnetic method capable of sleuthing inner wire breaks. (Wire rope Safety, 2017)A frequent cause for wire rope failure is corrosion. Th is is due to the use of a little lubrication or lubrication that has not penetrated inside the rope. The rope inspector will not see the wire rope corroding due to lubrication on the outside however the rope would be destroyed internally by corrosion and abrasion and when it goes to lift a heavy weight, it would create a great amount of damage. Another way damage can be caused it called jumping the sheave which is not where the rope does not slip/jump out of the sheave but it fails to get into the sheave of the wheel instead. brace wire ropes have a high break up point therefore can be used in racy environments such as Ladle cranes (Ladle cranes, 2017) as seen in Figure 4. However if the steel wire ropes stay in the heat for too long, the material anneals therefore making it dangerous.There are multiple ways we can analyse why the wire rope failing one of them organism microscopic analysis. The wire rope can be analysed through and through this method to see the cracks in the ste el. It can then be run through a scan Electron Microscope (Scanning electron microscope, 2017) done by roentgenogram analysis and X-ray mapping which can show every lift point of the wire as if the wire was extremely brittle.Pulley systems have been used for a very long time and can be traced back to Mesopotamia in 1500 B.C. (When was the pulley invented?, 2017) so we can see that it is a very useful technique to present day. Therefore I intermit that the reason behind the rope failing is due to fatigue. There are several safety precautions for exceeding the weight limit such as Flemish eye. However there too many fatigue reasons that surmount the limit of the rope such as the amount/types of stresses and environmental factors that can also be analysed through SEM (Scanning Electron Microscope) to see cracks in the wire rope.Question 3)Arc dyers mignonetteing is a common method that fuses metals together. The way this is done is by using a dyers mignonette power go forth that co uld be alternating (AC) or direct (DC) current that creates an electric kink between an electrode and the base material. (Arc join, 2016) This then melts the base material to its dyers mignonetteing point and then the melted metal will create a weld between the metals. The weld will then cool fusing them together (can be seen in figure 7). Arc welders must be trained and equip with PPE (Personal Protective Equipment) such as visors due to the fact that trend welding produces harmful Ultraviolet radiation and toxic fumes from metals. If they do not take these precautions UV radiation can lead to ocular damage and the toxic fumes can lead to occupational disease.A major(ip) defect that slew welding could have is cracks (Figure 8). There are many types of cracks at bottom the weld and it just now takes one type to fail a weld inspection. You cannot go over the crack with more welding to coating it up as the weld will not be strong over use especially in relation to the missile sway on the steel which would not last long and could cause damage therefore the weld needs to be filed/grinded out and done again. One type of cracking is called cold cracking. It is not noticeable at low gear however over time it will be because hydrogen absorbs into the weld puddle affecting the weld. This could be because of moisture seeping into the electrode in front welding. Another type of cracking is called hot cracking and this is noticeable right aft(prenominal) welding. The reasoning behind this crack could be poor joint flesh that would not diffuse the heat. One of the other reasons behind hot cracking could be impurities such as the presence of sulphur in the welding metal which could cause problems such as change the engine cooling system within the weld.Many precautions can be taken to avoid cracks within the arc weld such as checking your welding equipment i.e. test your machine in front you generate current to the electrode and keep your welding rod and met als in ironical conditions so hydrogen or sulphate does not affect your weld. You should also make sure your plates are clean and grinded well so the arc weld fit without any problems such as the welding joint.Steel has a very low carbon content between 0.05-0.25% which is diffuse to weld with because it would not harden by heat treatment. Therefore there will be less hardened regularizes in the heat bear on zone because as carbon content increases, welding gets harder because of the quenching action. The microstructure of the weld metal is needed for the alloy of the carbon steel but in carbon, carbon manganese and micro alloyed steel, the weld metal structure is mostly affected by the welding. The structure of Carbon steel is usually affected by things such as the cooling time, plastic strain, while etc.The Heat Affected Zone (HAZ) is the area of the steel plates that has had microstructure and properties modify by welding (Heat-affected zone, 2016). The speed and temperatu re of the welding plays a big fibre as it decides the spread of heat onto the parent material (HAZ diagram figure 9). Different types of processes such as electron beam welding gives off high concentrated limited amounts of heat that results in Heat affected zone. For arc welding in steel, the HAZ is split into three sections being the intercritical, supercritical and subcritical from a metallurgical point of view. Heat affected zones are impracticable to see because it makes it hard to manage the bending angle therefore the only way to remove the entire extension of the HAZ is to machine it away (Dealing with HAZ, 2017).Methods to analyse weld testing are utilized to guarantee the quality of the weld after it is finished. For the most part this refers to testing and analysis concentrated on the quality and quality of the weld, yet it may refer to actions to check for the position, potency of welds. A common method to analyse these welds are image-based such as X-ray using Machin e Vision (MV). This method is done by and inspector manually to look at images of the weld and come up with a conclusion of the quality and correctness of the weld.In conclusion, there are many deciding factors such as the microstructure when it comes to its behaviour and properties. We know that the cooling rate and composition of the welding is important in the formation of microstructures in the welding metal. I would recommend welding the steel in controlled situations at described above to prevent cracks. We know the carbon content of the steel increases therefore the weldability decreases and the hardness increases. I believe arc welding in a controlled situation such as dry conditions and testing machinery before use is a low risk of being affected by things such as sulphate and hydrogen.Question 1)Vehicle Axle (2017) in Wikipedia. useable at https//en.wikipedia.org/wiki/AxleVehicle_axlesAugust Wohler (2016) in Wikipedia. Available at https//en.wikipedia.org/wiki/August_W%C3% B6hlerFile BrittleAluminium320MPa S-N curve.svg (2016) in Wikipedia. Available at https//en.wikipedia.org/wiki/FileBrittleAluminium320MPa_S-N_Curve.svgHow do you break an axle? (2017) Available at https//www. write.com/home-garden/break-axle-7c5da780a7e83eb2Fractography (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/Fractographyhttps//en.wikipedia.org/wiki/Optical_microscope/media/FileOptical_microscope_nikon_alphaphot_%2B.jpgQuestion 2)Pulley Systems (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/PulleyRope_and_pulley_systemsCarbon steel rope (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/Wire_ropeConstructionWire rope Safety (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/Wire_ropeSafetyLadle cranes (2017) Available at http//www.casar.de/Rope-Selection/Ladle-CranesScanning electron microscope (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/Scanning_electron_microscopeMaterialsSEM Scanning (no date) Avail able at https//www.mri.psu.edu/materials-characterization-lab/characterization-techniques/scanning-electron-microscopy-semWhen was the pulley invented? (2017) Available at https//www.reference.com/history/pulley-invented-8dcaf2574d30b8eaWire rope bend (2017) in Wikipedia. Available at https//en.wikipedia.org/wiki/Wire_ropeQuestion 3)Arc welding (2016) in Wikipedia. Available at https//en.wikipedia.org/wiki/Arc_weldingWelding diagram (2003) Available at http//www.globalspec.com/reference/80954/203279/chapter-6-metal-arc-welding-with-coated-electrodesArc Welding Cracks (2016) in Wikipedia. Available at https//en.wikipedia.org/wiki/Welding_defect/media/FileWelding_cracks.svgHeat-affected zone (2016) in Wikipedia. Available at https//en.wikipedia.org/wiki/Heat-affected_zoneDealing with HAZ (2017) Available at http//www.thefabricator.com/article/shopmanagement/all-you-need-to-know-about-the-heat-affected-zone