What is difference between Hpdc and Lpdc?

What is difference between Hpdc and Lpdc?

LPDC is used when selecting castings with high air-tightness requirements. The production batch is large, and small and medium-sized non-ferrous metal castings without tightness requirements are HPDC. The difference is that LPDC parts can be strengthened by heat treatment, and the toughness can be greatly improved.

What are the casting defects and its remedies?

Casting defects are caused by non optimized process, failure of material, casting equipment. So the defects can be tolerated and repaired. In aluminum die casting the molten aluminum is poured or injected into metallic die. There are many sources to cast defects and have many names.

What is Castage shrinkage defect?

Shrinkage defects can occur when standard feed metal is not available to compensate for shrinkage as the thick metal solidifies. Shrinkage defects will have jagged or linear appearance. Shrinkage defects usually occur in either the cope or drag portion of the casting.

What is HPDC process?

High-Pressure Die Casting (HPDC) is an extremely efficient manufacturing method for producing various product forms. The process forces molten metal at high speed, and high pressure into a closed steel die cavity. The die has a stationary and moving half, both of which are mounted to the die casting machine’s platens.

What is pinhole defect?

Pinholes are a coating defect (holiday) can be prevented by the use of surface tension reducing agents to transport air bubbles to the surface of a coating.

What is hot tears?

noun. a crack formed in hot metal during cooling, caused by an improper pouring temperature or undue restraint.

What is porosity defect?

Porosity. Porosity is the most common casting defect, which can be caused by problems in the running system. To eliminate these problems, we use bespoke running systems that are tailored to each individual customer requirement. Trapped air and gasses can also cause porosity, either on the surface or inside the casting.

What is scabbing defect in casting?

Scab – This defect occurs in sand casting when a portion of the face of the mold lifts or breaks down and the recess left behind is filled by metal.

What is hot tear defect?

A hot tear is a defect that occurs during solidification of the casting. Hot tears are internal or external ragged discontinuities or crack on the casting surface, caused by rapid contraction occurring immediately after the metal solidified.

What is Hpdc pressure?

The mold is filled rapidly, and a very high pressure (up to 20 MPa) is maintained during the solidification process. Because of this high-velocity filling, HPDC can produce shapes that are more complex than permanent mold casting with much thinner walls.

What is vacuum casting process?

Vacuum casting is a casting process for elastomers using a vacuum to draw the liquid material into the mold. This process is used when air entrapment is a problem, there are intricate details or undercuts, or if the material is fiber or wire reinforced.

What is the use of pinhole?

Squinting and looking through a tiny hole made with a finger works similarly to a pinhole occluder, by blocking light through the outer parts of the eye’s lens….

What causes pinhole casting?

Molten metal can store a large quantity of gas in solution. Therefore, a large amount of the gas, dissolved in the liquid metal during melting, pouring and filling of the mold, is expelled from the metal as it solidifies. These dissolved gases form into small gas bubbles and pinholes in the casting.

What is cold shut in casting?

Definition of ‘cold shut’ A cold shut is a discontinuity that appears on the surface of cast metal as a result of two streams of liquid meeting and failing to unite. A cold shut is a fault in the surface of a piece of metal caused by two streams of molten metal not joining properly when the piece is being cast.

What causes porosity?

Porosity is caused by the absorption of nitrogen, oxygen and hydrogen in the molten weld pool which is then released on solidification to become trapped in the weld metal. Nitrogen and oxygen absorption in the weld pool usually originates from poor gas shielding.