Surface engineering technology used in industry for surface Essay

Surface engineering technology used in industry for surface modification( i.e surface treatment-surface thermo-chemical tratment - Essay Example This has been made feasible because steel is strong, flexible, and durable, thus, making it a suitable material for construction. However, there are instances where some modifications have to be made to the metal to make it suitable for some types of construction. The resolve to have steel that is strong, tough, wear, and shock resistant leads engineers to manipulate the surface of the metal, leaving its inner core intact (Davis, 2003). This process is called surface hardening of steel, and it can be done in many ways. Surface hardening techniques can be grouped into two main categories; local thermal treatment and thermochemical processes. The choice of treatment to be used depends on engineering requirement s as well as commercial competition. In this section, this article presents an overview of the procedures used to harden the surface of steel. Each describes the procedures involved in the two categories. 1.1 Thermo-Chemical Processes Engineers modify the local chemical composit ion of steel at the surfaces by induction of nitrogen, carbon or both. Sometimes they may also use boron. The techniques used in this category depend on the method of heat treatment applied and can further be broken down into four subcategories: i. Pack processes such as metalizing and pack carburizing ii. Salt-bath processes such as carbonitriding (cyanide hardening) iii. Gaseous processes such as gas nitriding and gas carburizing iv. Vacuum based processes including ion nitriding, carburizing, and plasma nitriding The most salient features of these processes are the processing temperature, mechanical properties and depth of the case, as well as the service behavior of the case’s core composite. Temperature is particularly significant because it affects the level of distortion directly. 1.1.1 Nitriding This can only be done on materials that have already been hardened and tempered. It produces better results when used with a range of alloys of steel that form stable nitrides such as vanadium, aluminium, tungsten, chromium, and molybdenum. The resultant nitrides are dispersed evenly throughout the surface of steel. Figure 1: Schematic diagram of a nitriding process. The process occurs at around 540 degrees Celsius where distortion does not take place. The nitride layer on the surface of the metal makes it expand, thus creating large, compressive stresses that in turn increase surface hardness and improve fatigue strength. In addition, the process also results in steel that has a reduced friction coefficient. Nitriding is, therefore, the best method to use when developing surfaces that are intended to minimize friction such as crank shafts and ball bearings. Advantages of Nitriding 1. It is easy to control the nitrogen

My First Car Essay Example | Topics and Well Written Essays - 1500 words

My First Car - Essay Example It came to the point where I became very exhausted having to ask someone to take me to all the places that I want to go. Luckily, I have a great friend that does not mind doing anything for me. He once told me, â€Å"Emmanuel, just let me know if you need me to do anything for you.† One day, I decided to take my friend up on his offer. I called him at 5:30 pm on a Monday. I said, â€Å"Can I speak to James?† The person on the other line said to me, â€Å"This is James, who is this?† â€Å"This is Emmanuel,† I said. â€Å"Ok, Emmanuel, what can I do for you? I hope it’s not going out because I have to go to work.† I then replied, â€Å"Well, since you’re about to go to work, what time are you going to be available?† He told me that it depended on what I wanted to do. â€Å"I just want to drive around, James.† He said, â€Å"Well, I really don’t have the time to do that right now as I am busy.† I told him this was fine and that perhaps we could make plans for another time to which he agreed. On Tuesday, I was thinking very deeply about what I was going to do about James and the fact that he did not have the time to drive around with me. It was a difficult situation, to say the least. The next morning I called James to ask him for a favor. He sounded wary at first as he asked me what the favor was. I then told him that I wanted to learn how to drive. He sounded surprised by my request since I had previously told him that I was scared to learn. I swallowed the fear in my throat and said, â€Å"If I want to go places, I need to learn how to drive myself. It’s too hard having to ask someone for help all the time.† He paused for a long moment before agreeing to help; however, he did have one stipulation: I had to buy my own car first. Purchasing a new car was an interesting experience for me. I had absolutely no idea how to go about it. I knew that I would need James’ hel p. The next thing I know, I called him and said: â€Å"James, I have something for you.† He asked, â€Å"What is it that you have for me?† I replied, â€Å"I have some gas money for you if you will take me to buy my first car.† Fortunately, James was very happy to do this. We drove to numerous car lots that day, but we could not find a car that was good enough for me to crash and just when we were about to give up, we saw a nice little Honda Accord, 1987, driving by with a â€Å"for sale† tag on it. Instantly, I said to James, â€Å"Look! There’s a car for sale! We need to go after it.† We hurried and made a u-turn. We finally caught up with the Honda Accord and asked the driver to stop. When he stopped, we told him that we were interested in purchasing his car. The name of the owner of the Honda Accord was Broke and we asked him how much he was selling the car for. He said he was selling it for $850.00. I said, â€Å"How about $500.00?â₠¬  He agreed to my price offer. I asked Broke, â€Å"Does this vehicle come with any warranty at all?† Broke looked at me and said, â€Å"No, you buy it as it is.† I replied, â€Å"Well since I am buying it as it is, I need to make you a lower offer.† Broke then asked me how much. I offered $375.00 and Broke said, â€Å"That’s the too low man, you need to go a little higher.† I said okay and offered about $400.00 and Broke again said no, that the price I offered was still too low. So James and I turned around and pretended we were about to leave.  Ã‚