Chvorinov''s rule, Other Engineering

Q. Why is it desirable to design a casting to have directional solidification sweeping from the extremities of the mould to riser based on Chvorinov's rule? What would be an ideal shape for a riser? Discuss a desirable shape from a practical perspective.

Ans. The optimum riser diameter for a given casting can be opened by a Chvorinov's Rule :

         Chvorinov's Rule : It states that the freezing time of a casting.

                            1   (V)2

                      t =  q2 (A)

 

q = solidification constant, depending on the composition of cast metal and the positioning of the mould cavity, like, along a vertical or a horizontal axis.

          V   = ratio of volume of the casting to its surface area.

          A 

         Values of (V)2 and freezing time have been found out by actual

                       (A) 

experiments for different metals and alloys and for different cylinder diameters.

Best riser is one whose (V)2 is 10% to 15 larger than that of the casting.

                                (A)

Riser Design : If no riser is provided during casting, the solidification will start from walls and liquid metal in the centre will be surrounded by a solidified shell and the contracting liquid will produced voids towards the centre of the casting. Further cooling of the solid in centre sets up undersirable stresses in the casting.

        Provision of risers overcomes these problems as these supply molten metal for a solidifying casting. For this purpose, the risers must be large enough to remain liquid after the casting has solidified and must contain sufficient metal to provide for the contraction losses. Further these should be so positioned that they continue to supply metal throughout the solidification period.

Posted Date: 8/3/2012 6:33:17 AM | Location : United States







Related Discussions:- Chvorinov''s rule, Assignment Help, Ask Question on Chvorinov''s rule, Get Answer, Expert's Help, Chvorinov''s rule Discussions

Write discussion on Chvorinov''s rule
Your posts are moderated
Related Questions
i have a project to be completed, the project is, How to make a device which warns you when your water reservoir is full?? i want the name of device needed and the way to complete

explain elecrochemical series and give its applications

I need the following corporate finance problems completed in an excel spreadsheet. How much would this cost? 1) An investment project requires a net investment of $100,000. The pr


AS A CONSULTANT YOU ARE REQUIRED TO HIGHLIGHT THE BASIS OF INTERNATIONAL AND SHOW WHY YOU WOULD RECOMMEND INTERNATIONAL TRADE TO THE GOVERNMENT OF GHANA

relationship between z plane and s plane in bilinear transformation method


We now have some idea about what models are available to simulate the flow over an aerofoil, and also how to use the Hanley package to apply these methods. Keep referring to you


ENGINE CYCLES The two commonly used cycles on which the I.C. engines operate are: 1Otto cycle.         2 Diesel cycle. 1 OTTO CYCLE: theoretical Otto cycle is shown i