Blow hole and pin hole porosity, Other Engineering

Difference between Blow hole and pin hole porosity

         Blow hole : They appear as cavities in a casting. When they are visible on the upper surface of the castings, they are cooled open blows. These blows are normally rounded and have smooth walls.

         Pin hole porosity : This defect occurs in the castings in the form of pin hole porosity or gas porosity. These porosities are caused by the gases absorbed by the molten metal. The gases commonly absorbed and hydrogen, oxygen and nitrogen, the later two forming oxides and nitrides respectively. It is mainly hydrogen which is responsible for the pin hole porosity.

Posted Date: 8/3/2012 2:35:13 AM | Location : United States

Related Discussions:- Blow hole and pin hole porosity, Assignment Help, Ask Question on Blow hole and pin hole porosity, Get Answer, Expert's Help, Blow hole and pin hole porosity Discussions

Write discussion on Blow hole and pin hole porosity
Your posts are moderated
Related Questions
Design a combinational logic circuit that will generate the square off all the combinations of three bit binary number represented by A,B,C

When should stock rather than debt to fund its operations? There are several reasons for an organization to problem inventory rather than financial obligations. The first is if

an electric bulb weighing 15n hangs from a point C by 2 strings AC and BC .string AC is inclined at 60degree to horizontal and BC at 45 degree to vertical.find tension in string.


a web application using any technology that accepts an email address and checks if the domain of the email address exists.

Auxiliary power unit oil System: A sump at the bottom of the gearbox collects the returning oil, in some APU's the rear face of the sump is finned and let into the intake plenu

Plastic molds are made of plaster of Paris (gypsum) or calcium sulphate, talc and silica flour is added in the plaster of Paris to improve strength and to control the time required

Ic Packages: Like transistors and other types of solid state components, IC's are mounted in packages, which protect them from moisture, dust and other types of contaminations.

Q 1.what is the difference between BJT and FET.What is Biasing?Discuss abt diffrent Biasing techniques?Write the advantages and Volatage divider biasing over other biasing?what is