0
State any three common green sand process defect and give their causes and remedies?
Pioh
ni mesti budak uitm yg ty ni...
Wiki User
∙ 15y ago
Add your answer:
Earn +20 pts
How can you tell whether cavities in a casting are due to porosity or to shrinkage?
Porosity is a defect, which results from air entrapment in the molten metal due to turbulent flow causing air bubbles. Usually, this defect is characterized by smooth and spherical pores, but if rough and angular it is most likely as a result of shrinkage dendrites. The mechanical properties associated with shrinkage is the thermal expansion of the molten metal when it solidifies and cools to room temperature, if the riser isn't properly designed to accommodate shrinkage, there would be dimensional changes and are usually in form of cracks.
Why Software doesn't wear out explain?
Hardware Failure Rates The illustration below depicts failure rate as a function of time for hardware. The relationship, often called the "bathtub curve," indicates the typical failure rate of individual components within a large batch. It shows that in say a batch of 100 products, a relatively large number will fail early on before settling down to a steady rate. Eventually, age and wear and tear get the better of all them and failure rates rise again near the end of the products life. To assist in quality control, many new batches of products are 'soak' tested for maybe 24 hours in a hostile environment (temperature/humidity/variation etc.) to pinpoint those that are likely to fail early on in their life, this also highlights any inherent design/production weaknesses. These early failure rates can be attributed to two things • Poor or unrefined initial design. Correcting this, results in much lower failure rates for successive batches of the product. • Manufacturing defects i.e. defects in the product brought about by poor assembly/materials etc. during production. Both types of failure can be corrected (either by refining the design, or by replacing broken components out in the field), which lead to the failure rate dropping to a steady-state level for some period of time. As time passes, however, the failure rates rise again as hardware components suffer from the cumulative effects of dust, vibration, abuse, temperature extremes and many other environmental maladies. Stated simply, "…The hardware begins to wear out."Software Engineering Topic 1 Page 10 Software Failure Rates Software is not susceptible to the same environmental problems that cause hardware to wear out. In theory, therefore, the failure rate curve for software should take the form shown below. Undiscovered defects in the first engineered version of the software will cause high failure rates early in the life of a program. However, these are corrected (hopefully without introducing other errors) and the curve flattens as shown. The implication is clear. Software doesn't wear out. However, it does deteriorate with maintenance as shown below. During its life, software will undergo changes and it is likely that some new defects will be introduced as a result of this, causing the failure rate curve to spike as shown above. Before the curve can return to the original steady-state failure rate (i.e. before the new bugs have been removed), another change is requested, causing the curve to spike again. Slowly, the minimum failure rate level begins to rise-- the software is deteriorating due to change. Thanks & Regards, Bastin Vinoth NG
What is meant by a defect in the GTAW process?
GTAW is the Gas-Tungsten Arc Welding process A defect means something's wrong with the weld. There are hundreds of kinds, and every kind of defect has a different cause--and sometimes there are seven or eight causes for one defect.
What defect of injector causes late injection in marine diesel engines?
the camshaft timing will cause the late injection process
What causes the thoracic hunp in Scoliosis?
There are many causes. The most common is of a birth defect where the tissue near the spine is abnormal. The spine then begins to show scoliosis during adolesence.
What is the difference between defect detection and defect prevention?
The defects detection is the validation process. The defects prevention is a verification process.
What is a type of neural tube defect?
spina bifida is the most common defect
Which disorders related to OCD and causes a person to be overly concerned with a body defect?
Body dismorphic disorder causes a person to be overly concerned with a body defect.
What is the most common procedure to repair a central defect?
Anterior colporrhaphy is the most common procedure to repair a central defect
What does the tragic hero have that causes him or her to fall?
A character defect.
What are the causes of birth defect?
born in the wrong age
What is the most common causes of amputation of the upper extremity in the US?
it is usually performed because of trauma or birth defect. Seldom is disease as great a contributing factor
What is defect detection?
During the manufacturing process, once the product is finished, a quality control process is usually followed where defects are detected--hence defect detection.
Does spina bifida have oligohydramnios?
Not usually. The defect that causes spina bifida is not related to the causes of oligohydramnios.
