Manufacturing Engineering & Technology
7th Edition
ISBN: 9780133128741
Author: Serope Kalpakjian, Steven Schmid
Publisher: Prentice Hall
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 10, Problem 29QLP
Why does porosity have detrimental effects on the
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
For sand-casting a steel rectangular plate with dimensions 80mm×120mm×20mm, a cylindrical
riser has to be designed. The height of the riser is equal to its diameter. The total solidification
time for the casting is 2 minutes. In Chvorinov‟s law for the estimation of the total solidification
time, exponent is to be taken as 2. For a solidification time of 3 minutes in the riser, the diameter
(in mm) of the riser is ____
A flat plate is to be cast in an open mold
whose bottom has a square shape that is 200
mm by 200 mm. The mold is 40 mm deep. A
total of 106 mm3 of molten aluminum is
poured into the mold. Solidification
shrinkage is known to be 6.0%. The linear
shrinkage due to thermal contraction after
solidification is 1.3%. If the availability of
molten metal in the mold allows the square
shape of the cast plate to maintain its 200
mm by 200 mm dimensions until
solidification is completed, determine the
final dimensions of the plate.
A riser in the shape of a sphere is to be designed for a sand casting mold. The casting is a rectangular plate,
with length = 100 mm, width = 50 mm, and thickness = 10 mm. If the total solidification time of the casting
itself is known to be 2.5 min, determine the diameter of the riser so that it will take 20% longer for the riser
to solidify.
%3D
%3!
Chapter 10 Solutions
Manufacturing Engineering & Technology
Ch. 10 - Explain why casting is an important manufacturing...Ch. 10 - Why do most metals shrink when they are cast?Ch. 10 - What are the differences between the...Ch. 10 - What are dendrites? Why are they called so?Ch. 10 - Describe the difference between short and long...Ch. 10 - What is superheat? Is it important? What are the...Ch. 10 - Define shrinkage and porosity. How can you tell...Ch. 10 - What is the function of chills? What are they made...Ch. 10 - Why is the Reynolds number important in casting?Ch. 10 - What is a sprue? What shape should a sprue have if...
Ch. 10 - How is fluidity defined? Why is it important?Ch. 10 - Explain the reasons for hot tearing in castings.Ch. 10 - Why is it important to remove dross or slag during...Ch. 10 - Why is Bernoullis equation important in casting?Ch. 10 - Describe thixocasting and rheocasting.Ch. 10 - What is Chvorinovs Rule?Ch. 10 - How is a blister related to a scab?Ch. 10 - Is there porosity in a chocolate bar? In an ice...Ch. 10 - Describe the stages involved in the contraction of...Ch. 10 - Explain the effects of mold materials on fluid...Ch. 10 - It is known that pouring metal at a high rate into...Ch. 10 - Describe the events depicted in Fig. 10.5.Ch. 10 - Would you be concerned about the fact that...Ch. 10 - Review Fig. 10.8 and make a summary, explaining...Ch. 10 - Make a sketch of volume vs. temperature for a...Ch. 10 - What practical demonstrations can you suggest to...Ch. 10 - Explain why a casting may have to be subjected to...Ch. 10 - List and explain the reasons why porosity can...Ch. 10 - Why does porosity have detrimental effects on the...Ch. 10 - A spoked handwheel is to be cast in gray iron. In...Ch. 10 - Which of the following considerations are...Ch. 10 - Explain why the constant C in Eq. (10.7) depends...Ch. 10 - Are external chills as effective as internal...Ch. 10 - Explain why, as shown in Table 10.1, gray cast...Ch. 10 - Referring to Fig. 10.11, explain why internal...Ch. 10 - Note the shape of the two risers shown in Fig....Ch. 10 - Is there any difference in the tendency for...Ch. 10 - What is the influence of the cross-sectional area...Ch. 10 - It has long been observed that (a) low pouring...Ch. 10 - In casting metal alloys, what would you expect to...Ch. 10 - If you inspect a typical cube of ice, you are...Ch. 10 - How can you tell whether cavities in a casting are...Ch. 10 - Describe the drawbacks to having a riser that is...Ch. 10 - Reproduce Fig. 10.2 for a casting that is...Ch. 10 - List the process variables that affect the...Ch. 10 - Assume that you have a method of measuring...Ch. 10 - A round casting is 0.2 m (7.9 in.) in diameter and...Ch. 10 - A cylinder with a diameter of 2.0 in. and a height...Ch. 10 - The constant C in Chvorinovs rule is given as 2.5...Ch. 10 - Pure copper is poured into a sand mold. The metal...Ch. 10 - For the sprue described in Problem 10.58, what...Ch. 10 - When designing patterns for casting, pattern...Ch. 10 - Can you devise fluidity tests other than that...Ch. 10 - Figure P10.55 indicates various defects and...Ch. 10 - The fluidity test shown in Fig. 10.9 illustrates...Ch. 10 - Utilizing the equipment and materials available in...Ch. 10 - One method of relieving stress concentrations in a...Ch. 10 - Describe the effects on mold design, including the...Ch. 10 - Small amounts of slag often persist after skimming...Ch. 10 - Design an experiment to measure the constants C...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- a riser in the shape of a sphere is to be designed for a sand casting mold. the casting is a rectangular plate, with length 200mm, width 100mm, and thickness 18mm. if the total solidification time of the casting itself is known to be 3.5 mm, determine the diameter of the riser so that it will take 25% longer for the riser to solidify. assume a value of 2 for ‘n’ m( the exponent in chvorinov’s rule). know the volume and surface area of a sphere.arrow_forwardA horizontal true centrifugal casting process is used to make brass bushings with the following dimensions: length = 10 cm, outside diameter = 15 cm, and inside diameter = 12 cm. (a) Determine the required rotational speed in order to obtain a G-factor of 70. (b) When operating at this speed, what is the centrifugal force per square meter (Pa) imposed by the molten metal on the inside wall of the mold?arrow_forwardWhen designing patterns for casting, patternmakers use special rulers that automatically incorporate solid shrinkage allowances into their designs. For example, a 12-in. patternmaker’s ruler is longer than 1 foot. How long should a patternmaker’s ruler be for making patterns for (a) aluminum castings and (b) high-manganese steel?arrow_forward
- Describe the stages involved in the contraction of metals during casting.(a) Contraction of the molten metals as it cools prior to its solidification.(b) Contraction of the metal during phase change from liquid to solid.(c) Contraction of the solidified metals as its temperature drops to ambient temperature.(d) All of above.(e) None of above.2. What kinds of defects in castings?(a) Hot tear.(b) Surface scar.(c) Plastic deformation.(d) Ductile flow.3. How does porosity have detrimental effects on the mechanical and physical properties ofcastings?(a) Pores in castings are resulted from internal discontinuities when that are prone topropagate under external stresses.(b) The toughness of a material will decrease as a result of porosity.(c) Physical properties, such as thermal and electrical conductivity, also be adverselyaffected by porosity.(d) Pores increase the strength and elastic modulus.(e) Porosity increases both the thermal and electrical conductivity4. Thermosetting plastics can…arrow_forwardWhich of these factors causes more porosity to form toward the interior of a casting rather than toward the outside? (a) Gasses are less soluble in the solid metal than the liquid, so solidified areas push dissolved gasses toward the interior. (b) Casting under a vacuum causes gasses near the liquid metal surface to be drawn out of the liquid during solidification. (c) The feeding structures of the mold are designed to force entrapped air into the center of the casting. (d) Draft on the mold wall forces air bubbles toward the interior of the solidifying metal. (e) None of the above Non-eutectic alloys (most commercial alloys) solidify over a temperature range. Which of the following statements explains how this affects the casting process. (a) Solidified non-eutectic alloys are especially difficult to remove from metal dies (b) Non-eutectic alloys have significantly less fluidity than pure metals or eutectic alloys. (c) Non-eutectic alloys solidify starting from the outside of the…arrow_forwardDetermine the time required to fill the mold cavity along with the riser as shown in the following figure. A slab of 1500 mm x 750 mm x 500 mm is required to be cast using a sand casting process. It was observed previously that the total solidification time (T) for this casting = 1.6 min. Find out the cylindrical riser dimensions (diameter to height ratio = 1) for a solidification time T = 5 min.arrow_forward
- What is a pattern? What are the consideration necessary while designing pattern in casting?arrow_forwardA flat plate is to be cast in an open mold whose bottom has a square shape of 12.5 cm by 12.5 cm. The mold is 7.0 cm deep. A total of 350 cm³ of molten aluminum is poured into the mold. Solidification shrinkage is known to be 6.25%, which is a volumetric contraction, not a linear contraction. Table 7.1 lists the linear shrinkage due to thermal contraction after solidification. If the availability of molten metal in the mold allows the square shape of the cast plate to maintain its square dimension until solidification is completed, determine the final dimensions (width and height) of the plate.arrow_forwardA square section riser be designed for a sand-casting mold. The casting itself is a quarter-cylinder with a diameter of 12cm and a length 20cm. The total solidification time for this casting 0.9 min. The square for the riser will have a height-to-width ratio of 2.0. Determine the dimensions of the riser so that it is total solidification time = 1.2 minarrow_forward
- A disk-shaped part is cast out of aluminium with a diameter of 630 mm and a thickness of 16 mm. If the mold constant is 2.2 sec/mm2 in Chvorinov's rule, how long will it take the casting to solidify?arrow_forwardDescribe the die casting process in detail. Use neat sketches for clarity. Differentiate clearly between hot-chamber die casting and cold-chamber die casting processes. What is the difference between true centrifugal and semi-centrifugal casting? Describe the centrifugal casting process in detail. Use neat sketches to elaborate your description.arrow_forwardWhich one is better for the casting structure (a) and (b) in the following figures? Why?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University Press
Mechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSON
Thermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEY
Mechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage Learning
Engineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY
Casting Metal: the Basics; Author: Casting the Future;https://www.youtube.com/watch?v=2CIcvB72dmk;License: Standard youtube license