Cambridge Engineering Selector CES Computer Science Essay

In this particular assignment we are going to find the best material for a part of land-based gas turbine. For this research we are going to use the Cambridge Engineering Selector (CFS) software. We are going to find the manufacturing process. We are going to make a report by the help of CES software on eco-audit for the existing material and the material we choose. We have some information and data given by the company on the existing material. The component shows below is the part of the land-based gas turbine.

j230comb

Fig. 1 The part of land-based gas turbine

It is made from Hastelloy X material which is a Nickel-Chromium-Iron-Molybdenum alloy. It has excellent strength and oxidation resistance. Its approximate chemical composition is Ni 47%, Cr 22%, Fe 18%, Mo 9%, and Co 1.5%. It has a good ductility that’s why it can be forged and can be cold-worked. So this material is good for welding.

The component has 0.75 m in diameter, 10 mm in thickness and 200 mm of depth. The component is on service for 10 years and need to be replaced. The component need to be operates on some require condition i.e. temperatures up to 800oC, good thermal shock and corrosion resistance. It should be capable of being manufactured by casting. By using the CES software we have to specify the manufacturing process. And if require we have to do coating to achieve the heat and corrosion resistance. We have some more data given which is Minimum Tensile Strength 300MPa, Has to operate above 550oC, Maximum thermal expansion 15 μ strain/o C, Minimum Yield Strength 300MPa.

Cambridge Engineering Selector (CES)

It is a software package which help designer to make decision over which materials and design process to use in the development of new equipment. We can use the CES software for general analysis and optimization applications by material universe data module. By the help of CES software we can design or redesign components with highest performance and lowest cost.

CES software consists of three levels.

Level 1 for Introductory-level students, providing introduction to the world of materials and processes and helping them to select the materials and processes with limited datasets of 67 materials and 75 processes.

Level 2 for Intermediate-level students, providing the structured methodology for more materials and processes in the depth investigations with 98 materials and 107 processes with more information.

Level 3 for Advanced/graduate students, providing the full materials and processes used in industry with added design notes with the vast selection of materials. In this particular level there are 3000 materials and more than 200 processes.

CES software consists of the following main windows.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesmain windows of ces.jpg

Fig. 2 CES main window

Browse – This window contains a list of the tables in the database and the classification tree for the selected table.

Select – This window is the central navigation point for selection projects, showing the selection settings, the project stages and the selection results.

Search – This window is used for text searches on records in the database.

Graph Stage – This window displays selection charts which show the relationships between attributes.

Limit Stage – This window is used to enter selection criteria as limits on individual attributes.

Datasheet – This window displays a list of attributes for individual records. There can be many of these on the screen at a time.

As the requirement of the assignment, the company ask for the more efficient and economical material for the land-based gas turbine part. The part should be fulfilling the required properties and condition. For the particular material for the part of the land-based gas turbine, level three is reliable containing more than 3300 materials.

In level three, by selection the ‘select’ windows it will show the selection data. In selection data pane there is an option to select materials universe: all bulk materials.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesselestion atage all bulk materials.jpg

Fig. 3 selection data pane (All bulk Materials)

The selection Results contains a list of all of the records that have passed the selection stages.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ces2945 materials.jpg

Fig. 4 All bulk Materials

Selection stage of CES

1. Selection with the TREE stage

To create a new tree stage selects new tree stage from the select menu or the click the tree button. The tree stage properties will appear. For the project, the material for the part of land-based gas turbine should be metals and alloys, so insert it.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesfirst tree for metals and alloys.jpg

Fig. 5 Tree stage (Metals and Alloys)

In the Tree Stage window, for a single relationship, click the Show button. This opens the Cell Contents dialog, listing the names of records that fulfil the link selection criterion for the row. In the Cell Contents dialog, Click on a column heading to sort the list by record name

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ces1607 materials.jpg

Fig. 6 All Metals and Alloys

By applying the condition of metals and alloys in this tree stage, it will show only the metals and alloys from all universe materials.

2. Selection by limit stage

To create a limit stage, select new limit stage from select menu or click the limit button in the selection stages pane of the select window. A limit stage window will appear, and the stage will be listed in the selection stages pane.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesfirst limit.jpg

Fig. 7 Limit selection stage

Before we going to apply all the limits, let’s check the requirements of the company. The company wants the part should be operate up to 800oC, so the maximum service temperature should be 800oC and it also require that it should be operate above 550oC so the minimum service temperature should be 550oC.

The tensile strength and yield strength should be minimum 300 MPa. The Maximum thermal expansion should be not more than 15 μstrain/ oC. However, the tensile strength and yield strength are mechanical properties and service temperature and thermal expansion are thermal properties of the material.

Tensile strength: – maximum load that a material can support without fracture when being stretched, divided by the original cross-sectional area of the material.

Yield strength: – The stress at the yield point. And the stress needed to produce a specified amount of plastic deformation.

Thermal expansion: – Increase in volume of a material as its temperature is increased, usually expressed as a fractional change in dimensions per unit temperature change. When the material is a solid, thermal expansion is usually described in terms of change in length, height, or thickness.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesapply limit mechanical properties.jpg

Fig. 8 Applying Yield strength and Tensile strength

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesthermal limits.jpg

Fig. 9 Applying service Temperature

By applying the mechanical and thermal properties of material, it will show 171 materials which fulfil the conditions.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ces171 materials.jpg

Fig. 10 Metals and Alloys after applying mechanical and thermal properties

Manufacturing process

It is important to make the right manufacturing decisions early in the design process, before the cost-penalty of making changes becomes too high. The selection of the most appropriate manufacturing process of which there are a very large number is one such decision. Taking a broad view, a process is a method for shaping or finishing or joining a material (Esawi, 1997). The kingdom of processes contains broad families: casting, deformation, moulding, machining, compaction of powders, and such like. Each family contains many classes: casting contains sand-casting, die-casting, and investment casting, for instance. These in turn have many members: there are many variants of sand-casting, some specialized to give greater precision, others modified to allow exceptional size, and still others adapted to deal with specific materials. The land-based gas turbine should be capable of being manufactured by casting.

By applying another tree stage for the manufacturing process in trees pane click on process universe and in shaping process, select the casting and insert it.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cestree manufacturing process.jpg

Fig. 11 Tree stage for manufacturing process

After applying the casting limit to the materials selected, it’s eliminated all the materials which can be shaped by casting. There are only 67 materials left.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ces67 materials after casting.jpg

Fig. 12 Materials which can be shaped by casting

As the company requirement the material should be half or less price than the original material. It is made of Hastelloy X material which is one the alloy of Ni-Cr alloy group.

The Hastelloy X materials cost is 15.7- 17.3 GBP/kg.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ceshastelloy x.jpg

Fig. 13 Hastelloy X materials details

By applying the graph for the price for the selected materials. The existing material price is 15.7- 17.3 GBP/kg and the requirement is the half and less than the existing price. By the help of the selection box it’s easy to eliminate the expensive materials from the graph. Selecting the materials from less than 9 GBP/kg by the help of selection box.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of cesprice graph.jpg

Fig. 14 The bar chart of selected material with price

After applying the condition of price, there are only 11 materials left.

C:UsersRANJANDesktopFINAL ASSIGNMENTHigh Temperature Materials and Applicationsphoto of ces11 materials.jpg

Fig. 15 Materials selected after the condition of price

Esawi, A. M. K. and Ashby M. F., ‘Computer-Based Selection of Manufacturing Processes’, Cambridge University Engineering Dept Report, CUED/C-EDC/TR50, May 1997.