Shrinkage cavities casting defects, Other Engineering

Q. Discuss briefly the causes and remedies of Shrinkage cavities casting defects.

                                                OR

 Why shrinkage cavities are caused in the casting ? Discuss methods used for eliminating them.

Ans. Shrinkage cavities caused by improper directional solidification are most with small sections abruptly.

         What happen in these sections is that there being a greater mass at the junction point compared to the legs, the junction point area becomes a hot spot with directional freezing progressing towards the hot spot, which in turn feeds the legs and develops the shrinkage cavity.

        The hot spot can be eliminated by either making the section more uniform or using chills near the cross-section of larger mass. Although every effort must be made to prevent isolation of heavy sections which can become 'hot spots', sometimes is becomes difficult.

        Under such circumstances, it is left to the foundry man to control the freezing by means of :

       (i) Special manipulation of the position of risers in mould,

       (ii) Controlling the speed of pouring,

       (iii) Utilizing hot metal in the risers,

       (iv) Using mould materials of different thermal characteristics.

Posted Date: 8/3/2012 2:31:59 AM | Location : United States







Related Discussions:- Shrinkage cavities casting defects, Assignment Help, Ask Question on Shrinkage cavities casting defects, Get Answer, Expert's Help, Shrinkage cavities casting defects Discussions

Write discussion on Shrinkage cavities casting defects
Your posts are moderated
Related Questions
Architecture of 8051

Review the lecture on BB document “Pharmacology …..” slide 6 where the solution for a 1st order system was demonstrated. The generic system is A(X)?(K1)?B(Y)?(K1’)?C(Z) 1. Cr


Exhaust duct arrangement in Aircraft: Exhaust ducts are invariably positioned to ensure that on the ground as the hot gases are directed away from the maintenance crews and air

what is the input to a process control system?

Prepare a list of questions that should be resolved in identifying each of the following problems: a. Develop an improved manual gearshift for a mountain bike. b. Develop a hands-f

how to generate random numbers in rectangular region?

Discuss the roles of international financial system in international business


Q. Discuss the classifications of plastics.                                                      OR      Discuss the general properties and classification of plastics.