Material Engineering - Why a mechanical engineer should study this subject

Mechanical engineering is a field of study that deals with physics, analysis, processes, manufacturing, design and materials. In taking up mechanical engineering, you need to learn not only the theories, computations and designs, but you also need to know the materials being used in mechanical and industrial processes and all its properties. Commonly, in fields and industries, chemical engineers are the ones who handle materials and its structures, but as a mechanical engineer, you also need to learn this staffs because you will be the one to use those materials for processing and manufacturing.

Brief history of material engineering

Material science is one of the oldest fields of subjects in engineering and sciences. Ever since the civilization started, materials already exist, being used and processed. In the early times, people in stone ages have been able to invent and use stones and other simple tools for their food hunting and survival. Centuries passed, people learned to make alloys, which provides greater properties of the materials. Up to this modern period, people still study and research for improvements of materials. 

Mechanical engineering and material engineering

Mechanical engineers are the ones who design and invent machines. In doing so, they need not only know the design and the mechanism of the machine, but also the appropriate materials to be used. This is why materials science is an important subject in mechanical engineering. Materials science, also known as materials engineering, is a branch of engineering and science that deals with the applications of properties of matters, such as its atomic structures and molecular scales. It incorporates the study of both physics and chemistry fundamentals. In the world of mechanical engineering, materials science is an important part of failure analysis and forensic engineering. In analyzing processes involved in mechanical engineering, the performance and output commonly depends on the properties of materials such as dislocations, grain materials, interference and heterogeneity. Before doing and using any materials, you need to know first its properties, and that is what materials science discusses about.

Knowing about material engineering is important.

Basic concepts and terminologies a mechanical engineer should know 

In studying materials science in your mechanical engineering degree, you need to learn the basic knowledge that are very useful and can be applied when designing a machine. As a mechanical engineer, you must know the classifications of materials which include metals, ceramics, semiconductors, polymers, composites and biomaterials which have different properties that would be your basis of selection for your design. You also need to know what processes these materials undergo and their applications in the industries. A mechanical engineer also handles the testing of the material, so you should need to know the different methods of testing materials.

Metals - Iron, Steel and Aluminum

Material is something that made of with matter form of one as well as more substances. This is also most used segment of any manufacturing or production unit. In this sense, any sorts of materials are the most essential part to create anything else from household products to building constructions. However, the terms of material is playing a most essential role in day to day life of people.

Apart from any others, materials are considered as the main source of mechanical engineering and industrial setting. Unprocessed raw material is used to made different types of finished products, which is used in different construction, distribution, and consumption.

There are various types of raw materials available to manage different needs such as:

Iron

Iron is a one chemical element within the sign of Fe as well as atomic number 26.  This is a one kind of metal in 1st transition series. Iron is also considered as the most general element for forming our complete planet Earth including both Earth's inner core and outer.  This is the 4th most common or required element in the earth coating. So, it is a most valuable and high required material in industrial settings and mechanical engineering sector.  Due to its flexible and long lasting quality this material is used in tiny product designing to large products designing.

Melted iron is a liquid

Steel

Steel is alloy of iron material and any others combined with carbon. While carbon is the main alloying element of steel and contain in the steel material within 0.002% to 2.1% as per the weight. However, steel is also containing some other elements to keep its durability and flexibility such as: carbon, silicon, sulfur, phosphorus, manganese, aluminum, nitrogen and oxygen. There are also some alloying elements deliberately combined to change the characteristics of steel such as: vanadium, titanium, boron, molybdenum, chromium, nickel, and manganese. Steel is one of the most precious and valuable element for different industrial settings and manufacturing units for production of different goods.

Aluminum

Aluminum is one chemical element within boron group in the atomic number of 13 and symbol Al.  This material looks silvery white and it never soluble in the water within the normal circumstances   Aluminum is also mentioned as the 3rd richest element after silicon and oxygen also it abundant element within the earth coating.  This material is making nearly about eight percentage of weight in the solid surface of earth.  This metal is also more chemically reactive, which native specimen is limited and rare to extreme decreasing of environments.  Apart from that, this material is a combination of more than 270 separate minerals in which main ore of this material is bauxite. This is also a low density mental, so most of the structural components are created from the Aluminium. Apart from these three, there are also numbers of materials available which are playing a most common role in the earth coating and in different manufacturing and mechanical production units. Now, there are also some new and advanced materials produced by combing these materials to make some long lasting structures.                        

Introduction to the Lathe

A lathe is considered as a machine gear that swivel the workpiece over its axis for performing different operations like sanding, cutting, drilling, knurling, deformation, turning,  and facing, with gears that’re applied with the workpiece for creating a point that has proportion approximately an axis of revolving.

Lathes are utilized in metalworking, woodturning, thermal spraying, metal spinning, parts reclamation as well as glass working. Most properly maintained metalworking lathes also could be utilized to deliver most solids of plane surface, revolution and helices or screw threads. Ornamental lathes could produce 3-dimensional solids of unbelievable complication. The materials could be held by either 1 or 2 centres, minimum one of which could be moved straight to lodge altering material length. Other work holding process comprise clamping the fastening the work approximately the axis of revolution utilizing a collet or chuck, or to any faceplate, utilizing dogs or clamps.  Instances of objects that could be produced over a lathe comprise gun barrels, candlestick holders, table legs, cue sticks, bowls, musical instruments, baseball bats, camshafts as well as crankshafts.

A green lathe in a metal workshop

Major categories of lathes:

Woodworking lathes

For you knowledge, woodworking lathes are considered as the oldest variety. In fact, all other diversities are come from these straightforward lathes. An adaptable horizontal metal bar – the instrument rest – amid the operator and material lodge the placing of shaping instruments, which are normally hand held. With wood, it’s normal practice to press as well as slide sandpaper adjacent to the still-spinning item after shaping to even the surface created with the help of metal shaping equipment. Also these are woodworking lathes regarding making plates and bowls, which have no straight metal bar, as the plate or bowl requires to be held only by one side from any metal facade plate. However, without this bar, there’s extremely little limit to the breadth of the portion being revolved.

Clue lathe

Clue lathe functions alike to turning as well as spinning lathe enabling for a properly radially equal cut regarding billiard cues. Also, they can be utilized to refinish cues that have been damaged over the years.

Reducing lathe

This kind of lathe is utilized in coin making where a wrap original is duplicated as well as decreased over the reducing lathe, delivering a master die.

Safety on lathes

Lathe is a power tool and it can seriously injure an individual if he misuses it or employ it regarding applications they’re not designed for. In fact objects could simply get caught up within spinning workpieces; operator must keep loose items like garments in a secured proximity from lathe tools. Some lathes do not comprise safety guards for preventing items from hurried out at the operators. In such cases, dust masks and goggles help decrease the danger of harm from airborne debris and dust.

Facts about lathes

All lathe tools, comprising metal lathes and wood lathes, have several critical elements. Lathe devices comprise a bed which offers a base regarding the device a tailstock and spindle to hold workload; a saddle for lodging house gears as well as other components.

Introduction to Welding – Modern Welding Methods

Welding is considered as sculptural or fabrication procedure what joins materials, normally thermoplastics or metals, by creating coalescence. This is often performed by liquefying the workpieces as well as incorporating a filler stuff to develop a puddle of molten substances which cools to turn out to be a powerful joint, sometimes with pressure utilized in combination with temperature of by itself for producing the weld. This is in disparity with brazing and soldering that comprise liquefying a lower melting point substance amid the workpieces to create a link among them, without liquefying the workpieces. Several different energy sources could be utilized for welding, comprising an electric arc, a gas frame, a laser, friction, ultrasound and an electron beam. Whilst most of the time an industrial procedure, welding might be done in several different atmospheres, comprising under water, open air, as well as within outer space.

Potentially welding is dangerous undertaking and safety measures are necessary to ignore electric shock, burns, vision damage, gasp of toxic fumes and gases as well as contact to intense ultraviolet emission. Till the conclusion of the nineteenth century, the lone welding procedure was forge welding, what blacksmith has utilized for centuries for joining steel and iron by heating as well as hammering. Oxyfuel welding and arc welding were amongst the 1st procedure to expand late towards the century, then electric resistance welding followed it. Technology in welding advanced very swiftly throughout the early twentieth century since World War I as well as II gaggle the requirement for inexpensive and reliable joining process. Following the war, different contemporary welding technologies were come into action.

Let’s have a look at the different types of modern welding methods available:

Shielded Metal Arc Welding

Known as stick welding that utilize a bar or in technical term it’s called an electrode which has a residue coating over it that melts or burns to develop a screen from oxygen, and few bars have packing metals incorporated to the wrapping to accelerate the welding procedure. Shielded metal arc welding is considered as the ideal procedure to weld outdoors.

Metal Insert Gas Welding (MIG)

MIG welding is a procedure which utilizes a wire pool for feeding wire to the joint as well as has a container of gas which gushes from the appliance to the welding grip to shelter the weld form air about it. The greatest portrayal in an assessment perspective is a cycle’s brake wire that has a cable running through which feeds incessantly to the joint, however; also this cable has a gas streaming via it that protects the weld from the air.

Tungsten Inert Gas Welding 

Also known as TIG welding is a torch which has a gas streaming through with a non delicate bar created from tungsten which warmth the metal as well as the packing metal is detained in other hand and physically incorporated when required. The non-consumable bar is only a bar that makes the arc to warmth the metal. It doesn’t put in to the welding packing material itself.                    

Materials Testing

Materials science, also known as materials engineering is one of the important subjects of any field of engineering especially mechanical engineering. When you study materials science, material testing is an important topic that a mechanical engineering student should learn because commonly, mechanical engineers are the ones who test materials before using them.

Why a material needs to be tested

Before a material or specimen is used on its function, a series of tests are being made to prove that it is on its proper conditions and to ensure safety. Common properties of materials being tested include hardness, tensile and compression strength, break load, shear and bearing strength, ductility, elastic limit, Young’s modulus, elongation, rupture strength, modulus of elasticity and rigidity,  and tear resistance. In the field of mechanical engineering, metals are the mostly used and therefore, the most commonly tested as well. In some other areas such as civil engineering, concretes, roads, and structures are also being tested before using them.

Common types of material testing in mechanical engineering

Metals are the materials being often used for designing machines and other mechanical tools. In testing materials, there are two major types being used: destructive and non-destructive testing.

A. Destructive testing – this test aims to bring out the material’s failure under a certain load. This type of test is easier to analyze than non-destructive testing, but a bit more costly because it damages the specimen partially or completely. The following are the most typical types of destructive testing used in mechanical engineering field.

• Hardness test – this type of test is used to measure the material’s resistance to indentation over a specific period. Brinell hardness test is the most common type of hardness test. Rockwell, Vickers and Shore Sclerospcope are also used. 
• Stress test – this test is used to measure the constancy and stability of a given specimen and system.
• Impact test – this test is used to determine the amount the energy absorbed by the material up to its fracture state at a high velocity. 
• Crash test – this test is commonly used on automobiles which aims to determine the ability of the material when being crashed over a given time and speed.

B. Non-destructive test – this test is commonly used in testing larger specimen such as roads, dams, bridges, and infrastructures. These large specimens cost high and subjecting them into destructive testing is somewhat more costly. Except for the buildings that are established in earthquake zones, these buildings are often tested on how well it can withstand earthquake. But aside from those, non-destructive are typically used. Common non-destructive tests include ultra-sonic, Eddy current testing, liquid penetrate and radiographic analysis.

Introduction to Metal Alloys

In engineering topics, when we talk about materials, these are the basic substances combined and produced to be used in operations, processes and building machines. During early times, only natural materials are available such as stones and woods. But as modernization approaches, materials that are made by men are now available and are continuously being improved. Typically, materials may fall into four major classifications: metals and metal alloys, ceramics, polymers and composites. Metals are the most common materials being used and handled by mechanical engineers especially in designing and building machines. Metal alloys are also used in various thermocouple types to measure temperatures.

Metal alloys

Metal alloys are the most common materials used by mechanical engineers in designing and inventing machines. Metal alloys are mixtures of two or more metals combined to produce a better property. Metal alloys also play an important role in the history of civilization. The period was named after a certain metal alloy was discovered and was widely used over that era such as bronze ages and iron era.
There are two major types of metal alloys:

A. Ferrous metals – these are metal alloys that contain amount of iron. Typical ferrous metals used in engineering are the following:
* Cast iron – an iron formed by casting. These are commonly used for making gears, block and brake drums.
* Carbon steel – used to make drill bits and other cutting tools. This type can be classified as low, medium and high carbon steel depending on the amount of carbon it contains. Low carbon steel usually contains 0.1 to 0.25% of carbon and is used for carburizing. Medium carbon steel has 0.25 to 0.50% carbons and is usually tempered to hardness. High carbon steel contains more than 0.5% of carbon and is commonly used for wear-resisting parts such as springs.
* Stainless steel – alloy of iron, nickel and chromium.
* Wrought steel – commonly made by hammering, rolling or drawing and is used for bars and tube pipes.

B. Non-ferrous metal alloys – metal alloys that do not contain iron. Common types are the following:
* Brass – alloy of copper and zinc commonly used for screws, pistons, piston rods and shafts.
* Bronze – alloy of copper and tin, with small amount of phosphorous and is commonly used for clutch disks and pump rods.

Metal processes and heat treatment

Aside from adding an alloy to a metal, metal treatment and processes are done to achieve greater property. Common treatments and processes are the following:

• Annealing – process used to soften metal to improve its machineability.
• Hardening – usually done with quenching process to increase hardness of metals.
• Normalizing – used to provide uniform structure of metals.
• Stress relieving – used to reduce residual stress of metal.