FMEA (Failure Mode Effect Analysis)

Manufacturing industries face many problems while they manufacture some component in terms of planning, design, process, inspection, monitoring and in end results. FMEA (Failure Mode Effect Analysis) is a tool that can assist the concerned person with the facility of getting the forecast of how the things should go to have the minimum failures and have a constant watch over the various events going on simultaneously with equal effectiveness in all. FMEA provides the data about the possible causes of failure their severity and detection with the data from past experiences so that those errors can be rectified into future. Our project deals with one of those components “The Processes” and the carrying out the FMEA for the same at Fine Cast Industries

Casting is one of the oldest manufacturing process dating back to more than six thousand years. The products of the process known as casting are used extensively in engines, machine tools, automobile, aeroplane, house-hold appliances and many other fields. In fact, all metal cast at some stage of their production. Wrought materials are produced from ingots are cast in ingot moulds.
Casting can be divided into six general classes commercially known as plain grey cast iron, alloy cast iron, malleable iron, steel, alloy steel and nonferrous casting. Most foundries specialize in one or two of the above types. It is rare that a foundary attempts at making all the six types. Castability of metals depend on many factors and castability index is high if the material has high fluidity, low shrinkage, low affinity for absorbing gases, low stresses and uniform strength. Material which are considered exceptionally good for casting include cast iron, copper base alloy, zinc, aluminium, nickel and magnesium. Some of the typical castings include pulley, flywheel, engine and machine blocks, machine tool beds, gear blanks, turbine blades, C.I. pipes

Blow holes are bubbles of gas entrapped inside the casting. Both are caused by gases carried by hot metal. Blow holes are also caused by poor permeability of sand, too fine sand grains, over rammed moulds or insufficient venting.
 Causes:
 Unnecessary moisture in the moulding sand.
 Low permeability and excessive fine grain sands.
 Use of excessive organic binders.
 Cores neither properly baked not adequately vented.
 Remedies :
 Regulating the moisture content.
 Baked cores properly.
 Cores and moulds should be properly vented.
 Proper use of organic binders. (F) Porosity :
This defects occurs in the casting in the form of pin hole porosity or gas porosity. Hydrogen is responsible for pin porosity. Gases will be absorbed b liquid metal. Ehen the metal solidifies, the solubility decrease and gases will be released and create small voids throughout the casting called porosity.
 Causes :
 High moisture and low permeability.
 Gas dissolved in metal charge.
 Less flux used.
 High pouring temperature.
 Remedies :
 Increase flux proportions.
 Ensure effective degassing.
 Reduce moisture an increase permeability.
(G) Hot tearing : This defect, also called hot cracking occur when the casting is restrained or early stages of cooling after solidification.
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