Bicycle By Ragad and Hiba The History of Bicycle:
In 1816 the German Baron Karl von Drais devised a steerable hobbyhorse, and within a few years, hobby-horse riding was a fashionablepastime in Europe. Riders also discovered that they could ride thedevice with their feet off the ground without losing their balance. Andso, in 1840, a Scottish black-smith named Kirkpatrick Macmillan madea two-wheel device that was operated by a treadle. A couple decadeslater, a Frenchman, Ernest Michaux, designed a hobby horse thatutilized cranks and rotating pedals connected to the front axle. What Materials used in Bicycle??
The old bicycle made of: Titanium aluminum carbon fiber The new bicycle made of: Steel Aluminum Titanium Carbon fiber Steel: The chemical formula of the steel is Fe3C.
The properties of steel vary widely,depending on its alloying elements. The production of steel benefits theWorld in great ways. First, thestandard of living goes higher asthere exist new jobs in banking, ironore and manganese mining, officejobs, transport jobs. The steel recycle. If we only recycleone-tenth of the cans we now throwaway, we'd save about 3.2 billion ofthem every year. Advantage and Disadvantages:
Steel has the highest strengthto weight ratio of any buildingmaterial. No twisting or warping. Fire parapets can beeliminated. Slower aging process with lessmaintenance. Easily disassembled forrepairs Disadvantages: Heavy and thus expensive totransport. Steel is an excellent thermalconductor requiring additionalexterior insulation or thermalbreaks to overcome thisdisadvantage Steel components can rust if leftexposed in marine climates. Finding steel roof trusses isdifficult in most areas Aluminum: The chemical formula of aluminum is A13.
Aluminum is a metallic element, and itsstructure is very similar to most othermetal. Aluminum is made up of crystals It is not soluble in water under. Aluminum is the most abundant metalin the Earth's crust. Recycling aluminum cans is easy.When they are empty, rinse them out sothey are clean and either return them tothe store for deposit or recycle Advantage and Disadvantages:
Won't swell, chip or rust. Does not deteriorate. Reduced weight. increased strength &durability. Covers can be retrofitted forexisting structures. Low Surface Hardness Disadvantage: Aluminum is more expensivethan steel Aluminum can corrode quicklyif suitable precautions againstelectrolysis are not taken. Aluminum can be water- stained easily. Titanium: Titanium is chemical elementwith the symbol Ti and atomicnumber 22. Transition metal with a silvercolor. White metal when pure. Titanium is as strong as somesteels. Titanium is transition metal. The metal has a low density. Advantage and Disadvantages:
It is corrosive resistant. It can withstand hightemperatures. Light but Strong. has excellent corrosionresistance. Disadvantages: Expensive metal. Processes for forming andjoining titanium are complexand expensive. Expensive to cast. Carbon fiber There is no single formula for a carbon fiber. is a
Carbon fiber is crystallinematerial. White metal when pure. High chemical resistivity. Rigid materials that areresistant to stretching andcompression. a black, lustrous solid Advantage : Advantage: It can be formed to most any shape.
it's non-corroding. High wear resistivity and moisture absorbance. High thermal resistivity under non oxygen atmosphere. High modules {200~650Gpa} and high rigidity. sam.davyson.com/.../aluminium/.../structure.html We hope you like it. By Hiba and Ragad