AMIE INDIA Students Forum

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Can u tell me any other source to get section A question papers To whom I have to contact

contact to iei local office or contact jain brothers delhi u can get.
you may also get study material from jain brothers

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hi friends
importatant questions of sec a plz send a mail to parameshwaranpraveen@yahoo.in

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[quote="p.praveen"]hi friends
importatant questions of sec a

season cracking, griffth theory, c curve in heat treatment,
slip, twin , Hot working Cold working

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Hi friends pl send me sec b mechanical engineering question papers
Also send sec b mechanical study materials

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Casting defect
Shrinkage defects
Shrinkage defects occur when feed metal is not available to compensate for shrinkage as the metal solidifies. Shrinkage defects can be split into two different types: open shrinkage defects and closed shrinkage defects. Open shrinkage defects are open to the atmosphere, therefore as the shrinkage cavity forms air compensates. There are two types of open air defects: pipes and caved surfaces. Pipes form at the surface of the casting and burrow into the casting, while caved surfaces are shallow cavities that form across the surface of the casting.[3]
Closed shrinkage defects, also known as shrinkage porosity, are defects that form within the casting. Isolated pools of liquid form inside solidified metal, which are called hot spots. The shrinkage defect usually forms at the top of the hot spots. They require a nucleation point, so impurities and dissolved gas can induce closed shrinkage defects. The defects are broken up into macroporosity and microporosity (or microshrinkage), where macroporosity can be seen by the naked eye and microporosity cannot.[3][4]

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sec b notes


Pouring metal defects
There are three main defects for this category: misruns, cold shuts, and inclusions. A misrun is when the liquid metal does not completely fill the mold cavity, leaving an unfilled portion. Cold shuts occur when two fronts of liquid metal do not fuse properly in the mold cavity, which causes a weak spot. Both are caused by either a lack of fluidity in the molten metal or the cross-section is too narrow. The fluidity can be increased by changing the chemical composition of the metal or by increasing the pouring temperature. Another possible cause is back pressure from improperly vented mold cavities.[11]
Two more closely related problems are misruns and cold shuts, both involve the material freezing before it completely fills the mold cavity. The castability and fluidity of the material can be large factors with these problems. Fluidity affects the minimum section thickness that can be cast, the maximum length of a thin section, how fine of a detail that can be cast, and the accuracy of filling mold extremities. There are various ways of measuring the fluidity of a material, although it usually involves using a standard mold shape and measuring how far the material flows. Fluidity is affected by the composition of the material, freezing temperature or range, surface tension of oxide films, and, most importantly, the pouring temperature. The higher the pouring temperature the greater the fluidity, however excessive temperatures can be detrimental. High pouring temperatures can lead to a reaction between the material and the mold; in casting processes that use a porous mold material the material may even penetrate the mold material.[12]
The point at which the material cannot flow is called the coherency point. The point is difficult to predict in mold design because it is dependent on the solid fraction, the structure of the solidified particles, and the local shear strain rate of the fluid. Usually this value ranges from 0.4 to 0.8.[13]
An inclusion is a metal contamination of dross, if it is a solid, or slag, if is a liquid. These usually are metal oxides, nitrides, carbides, calcides, or sulfides; they can come from material that is eroded from furnace or ladle linings, or contaminates from the mold. There are a number of ways to minimize this contamination. In order to reduce oxide formation the metal can be melted with a flux, in a vacuum, or in an inert atmosphere. Other ingredients can be add to the mixture to cause the dross to float to the top where it can be skimmed off before the metal is poured into the mold. If this is not practical, then a special ladle that pours the metal from the bottom can be used. Another option is to install ceramic filters into the gating system. Otherwise swirl gates can be formed which swirl the liquid metal as it is poured in, which forces lighter inclusions to the center can keep them out of the casting.[14][15] If some of the dross or slag gets folded into the molten metal then its known as an entrainment defect.
[edit] Metallurgical defects
There are two defects in this category: hot tears and hot spots. Hot tears are failures in the casting that occur as the casting cools. This happens because the metal is weak when it is hot and the residual stresses in the material can cause the casting the fail as it cools. Proper casting design prevents this type of defect.[2]
Hot spots are areas on the surface of casting that are very hard because it chilled more quickly than the surrounding. This type of defect can be avoided by proper cooling practices or by changing the chemical composition of the metal.[2]

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sec b notes for mechanical engineering
] Pouring metal defects
There are three main defects for this category: misruns, cold shuts, and inclusions. A misrun is when the liquid metal does not completely fill the mold cavity, leaving an unfilled portion. Cold shuts occur when two fronts of liquid metal do not fuse properly in the mold cavity, which causes a weak spot. Both are caused by either a lack of fluidity in the molten metal or the cross-section is too narrow. The fluidity can be increased by changing the chemical composition of the metal or by increasing the pouring temperature. Another possible cause is back pressure from improperly vented mold cavities.[11]
Two more closely related problems are misruns and cold shuts, both involve the material freezing before it completely fills the mold cavity. The castability and fluidity of the material can be large factors with these problems. Fluidity affects the minimum section thickness that can be cast, the maximum length of a thin section, how fine of a detail that can be cast, and the accuracy of filling mold extremities. There are various ways of measuring the fluidity of a material, although it usually involves using a standard mold shape and measuring how far the material flows. Fluidity is affected by the composition of the material, freezing temperature or range, surface tension of oxide films, and, most importantly, the pouring temperature. The higher the pouring temperature the greater the fluidity, however excessive temperatures can be detrimental. High pouring temperatures can lead to a reaction between the material and the mold; in casting processes that use a porous mold material the material may even penetrate the mold material.[12]
The point at which the material cannot flow is called the coherency point. The point is difficult to predict in mold design because it is dependent on the solid fraction, the structure of the solidified particles, and the local shear strain rate of the fluid. Usually this value ranges from 0.4 to 0.8.[13]
An inclusion is a metal contamination of dross, if it is a solid, or slag, if is a liquid. These usually are metal oxides, nitrides, carbides, calcides, or sulfides; they can come from material that is eroded from furnace or ladle linings, or contaminates from the mold. There are a number of ways to minimize this contamination. In order to reduce oxide formation the metal can be melted with a flux, in a vacuum, or in an inert atmosphere. Other ingredients can be add to the mixture to cause the dross to float to the top where it can be skimmed off before the metal is poured into the mold. If this is not practical, then a special ladle that pours the metal from the bottom can be used. Another option is to install ceramic filters into the gating system. Otherwise swirl gates can be formed which swirl the liquid metal as it is poured in, which forces lighter inclusions to the center can keep them out of the casting.[14][15] If some of the dross or slag gets folded into the molten metal then its known as an entrainment defect.
[edit] Metallurgical defects
There are two defects in this category: hot tears and hot spots. Hot tears are failures in the casting that occur as the casting cools. This happens because the metal is weak when it is hot and the residual stresses in the material can cause the casting the fail as it cools. Proper casting design prevents this type of defect.[2]
Hot spots are areas on the surface of casting that are very hard because it chilled more quickly than the surrounding. This type of defect can be avoided by proper cooling practices or by changing the chemical composition of the metal.[2]

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hi frinds


for sec b manufacturing technology refer Hajra chaudry
for sec b Strength of materials refer R.K. Rajput

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Project management notes

2. Organizing for Project Management
2.1 What is Project Management?
The management of construction projects requires knowledge of modern management as well as an understanding of the design and construction process. Construction projects have a specific set of objectives and constraints such as a required time frame for completion. While the relevant technology, institutional arrangements or processes will differ, the management of such projects has much in common with the management of similar types of projects in other specialty or technology domains such as aerospace, pharmaceutical and energy developments.
Generally, project management is distinguished from the general management of corporations by the mission-oriented nature of a project. A project organization will generally be terminated when the mission is accomplished. According to the Project Management Institute, the discipline of project management can be defined as follows: [1]
Project management is the art of directing and coordinating human and material resources throughout the life of a project by using modern management techniques to achieve predetermined objectives of scope, cost, time, quality and participation satisfaction.
By contrast, the general management of business and industrial corporations assumes a broader outlook with greater continuity of operations. Nevertheless, there are sufficient similarities as well as differences between the two so that modern management techniques developed for general management may be adapted for project management.
The basic ingredients for a project management framework [2] may be represented schematically in Figure 2-1. A working knowledge of general management and familiarity with the special knowledge domain related to the project are indispensable. Supporting disciplines such as computer science and decision science may also play an important role. In fact, modern management practices and various special knowledge domains have absorbed various techniques or tools which were once identified only with the supporting disciplines. For example, computer-based information systems and decision support systems are now common-place tools for general management. Similarly, many operations research techniques such as linear programming and network analysis are now widely used in many knowledge or application domains. Hence, the representation in Figure 2-1 reflects only the sources from which the project management framework evolves.

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notes on organisation
2.4 Effects of Project Risks on Organization
The uncertainty in undertaking a construction project comes from many sources and often involves many participants in the project. Since each participant tries to minimize its own risk, the conflicts among various participants can be detrimental to the project. Only the owner has the power to moderate such conflicts as it alone holds the key to risk assignment through proper contractual relations with other participants. Failure to recognize this responsibility by the owner often leads to undesirable results. In recent years, the concept of "risk sharing/risk assignment" contracts has gained acceptance by the federal government. [4] Since this type of contract acknowledges the responsibilities of the owners, the contract prices are expected to be lower than those in which all risks are assigned to contractors.
In approaching the problem of uncertainty, it is important to recognize that incentives must be provided if any of the participants is expected to take a greater risk. The willingness of a participant to accept risks often reflects the professional competence of that participant as well as its propensity to risk. However, society's perception of the potential liabilities of the participant can affect the attitude of risk-taking for all participants. When a claim is made against one of the participants, it is difficult for the public to know whether a fraud has been committed, or simply that an accident has occurred.
Risks in construction projects may be classified in a number of ways. [5] One form of classification is as follows:
1. Socioeconomic factors
o Environmental protection
o Public safety regulation
o Economic instability
o Exchange rate fluctuation
2. Organizational relationships
o Contractual relations
o Attitudes of participants
o Communication
3. Technological problems
o Design assumptions
o Site conditions
o Construction procedures
o Construction occupational safety
The environmental protection movement has contributed to the uncertainty for construction because of the inability to know what will be required and how long it will take to obtain approval from the regulatory agencies. The requirements of continued re-evaluation of problems and the lack of definitive criteria which are practical have also resulted in added costs. Public safety regulations have similar effects, which have been most noticeable in the energy field involving nuclear power plants and coal mining. The situation has created constantly shifting guidelines for engineers, constructors and owners as projects move through the stages of planning to construction. These moving targets add a significant new dimension of uncertainty which can make it virtually impossible to schedule and complete work at budgeted cost. Economic conditions of the past decade have further reinforced the climate of uncertainty with high inflation and interest rates. The deregulation of financial institutions has also generated unanticipated problems related to the financing of construction.
Uncertainty stemming from regulatory agencies, environmental issues and financial aspects of construction should be at least mitigated or ideally eliminated. Owners are keenly interested in achieving some form of breakthrough that will lower the costs of projects and mitigate or eliminate lengthy delays. Such breakthroughs are seldom planned. Generally, they happen when the right conditions exist, such as when innovation is permitted or when a basis for incentive or reward exists. However, there is a long way to go before a true partnership of all parties involved can be forged.
During periods of economic expansion, major capital expenditures are made by industries and bid up the cost of construction. In order to control costs, some owners attempt to use fixed price contracts so that the risks of unforeseen contingencies related to an overheated economy are passed on to contractors. However, contractors will raise their prices to compensate for the additional risks.
The risks related to organizational relationships may appear to be unnecessary but are quite real. Strained relationships may develop between various organizations involved in the design/construct process. When problems occur, discussions often center on responsibilities rather than project needs at a time when the focus should be on solving the problems. Cooperation and communication between the parties are discouraged for fear of the effects of impending litigation. This barrier to communication results from the ill-conceived notion that uncertainties resulting from technological problems can be eliminated by appropriate contract terms. The net result has been an increase in the costs of constructed facilities.
The risks related to technological problems are familiar to the design/construct professions which have some degree of control over this category. However, because of rapid advances in new technologies which present new problems to designers and constructors, technological risk has become greater in many instances. Certain design assumptions which have served the professions well in the past may become obsolete in dealing with new types of facilities which may have greater complexity or scale or both. Site conditions, particularly subsurface conditions which always present some degree of uncertainty, can create an even greater degree of uncertainty for facilities with heretofore unknown characteristics during operation. Because construction procedures may not have been fully anticipated, the design may have to be modified after construction has begun. An example of facilities which have encountered such uncertainty is the nuclear power plant, and many owners, designers and contractors have suffered for undertaking such projects.
If each of the problems cited above can cause uncertainty, the combination of such problems is often regarded by all parties as being out of control and inherently risky. Thus, the issue of liability has taken on major proportions and has influenced the practices of engineers and constructors, who in turn have influenced the actions of the owners.
Many owners have begun to understand the problems of risks and are seeking to address some of these problems. For example, some owners are turning to those organizations that offer complete capabilities in planning, design, and construction, and tend to avoid breaking the project into major components to be undertaken individually by specialty participants. Proper coordination throughout the project duration and good organizational communication can avoid delays and costs resulting from fragmentation of services, even though the components from various services are eventually integrated.
Attitudes of cooperation can be readily applied to the private sector, but only in special circumstances can they be applied to the public sector. The ability to deal with complex issues is often precluded in the competitive bidding which is usually required in the public sector. The situation becomes more difficult with the proliferation of regulatory requirements and resulting delays in design and construction while awaiting approvals from government officials who do not participate in the risks of the project.