Solving Problems of Porosity in Die Casting Parts. Porosity in die casting parts is an important issue in metal-working. Porosity, in the science of materials, refers to the presence of gaps or bubbles inside a metal structure. High porosity tends …
Continue reading
Category Archives: Diecasting Process
General Information about Die Casting Draft Angles
General Information about Die Casting Draft Angles. Draft Angle is the sloping required in manufacturing aluminum die casting products. Because it facilitates ejection, this feature is often highly considered by aluminum die casting manufacturing companies.
Die Casting Draft Angles apply to both the pattern and the castings. Pattern Draft Angle is the considerable degree of tilt on the surface of the pattern. It allows the ejection of the casting from its mold. Casting Draft Angle on the other hand is the draft angle on the casting itself. It is the actual sloping seen on the castings.
Although the computation of draft angles is frequently generalized, the interior and the exterior surface of the die cast wall are highly considered. The draft angle recommended for the interior wall is twice as much as the external surface to facilitate ejection when the aluminum alloy harden and shrink.
In some instances, most particularly in the production of precision metals used by electronics industries, draft angle considerable varies. It must be specified in the design in order to guarantee efficient and effective performance of electronic gadgets, appliances, furniture and lighting fixtures etc. which uses these materials in their manufacturing process.
Draft Angle is also considered in designing the parting line and determining the parting line tolerance. The parting line is the point where the two halves of the casting mold meet. In most cases this line defines the internal and external surfaces of die cast parts. Minor errors in die casting applications includes errors or faulty in parting line designs.
Tons of aluminum products worldwide are made efficient just because a simple feature like draft angle was never taken for granted.
This is the blog on the Kinetic Die Casting Company web site. Kinetic writes about Aluminum Alloys for Die Casting. Look at this website page for more details: www.kineticdiecasting.com/casting_aluminum.html. Contact Kinetic Die Casting Company at 818-982-9200 or email us at sales@kineticdc.com. Use this webpage to request “die casting part prices” www.kineticdiecasting.com/replyform.html
Sources of Porosity in Die Castings
Sources of Porosity in Die Castings. The formation of bubbles in the castings results to die casting porosity. Porosity in die castings in defects caused by bubbles, often resulting from machine inefficiency, temperature variances, etc.
The following enumerates the most common sources of porosity in die castings.
Air Entrainment
Once air is trapped in the castings upon pouring of metallic substance into the die and the same air was not able to escape during solidification, a metal casting defect is expected to result from it. Both the temperature and the pressure directly affect the formation of such die casting porosity.
Blow Holes
When from a core, gas bubbles are blown into the liquefied metal, causing holes when solidified. This is also known as blisters.
Oxides
Some defects in die casting are caused by oxides. Oxide formation causes defects on the surface or in the subsurface of the die cast parts. In steel castings for example, the removal of inclusion material by blasting causes associated porosity. These are the grassy areas in steel castings.
Pinholes
Pinholes are characterized by the formation of tiny bubbles caused by less soluble gases. During solidification, soluble gases must dissolve upon combination with liquefied metal. Once insoluble gasses remain, defects such as pinholes will appear on the castings.
Shrinkage
Shrinkage normally occurs during solidification of liquid metal. An allowable degree of shrinkages is considered by die casting manufacturing companies. However when shrinkages goes beyond the allowable level forming a defective casting, this is considered a manufacturing cost. Die casting products are often deformed due to shrinkages in various forms.
This is the blog on the Kinetic Die Casting Company web site. KDC also writes about Porosity in Die Casting. Look at this website page for more details: www.kineticdiecasting.com/porosity.html. Contact Kinetic Die Casting Company at 818-982-9200 or email us at sales@kineticdc.com. Use this webpage to request “die casting part prices” www.kineticdiecasting.com/replyform.html
Additional Technical Die Casting Terms
Additional Technical Die Casting Terms. The pillar of modern manufacturing industries nowadays is the metal forming industries. The process of die casting aluminum metals produces tons of precision metal parts, primary products and by-products. Besides the basic terms used in die casting manufacturing procedure, it is important to know additional technical die casting terms.
Dowel Pin
It is a semi-permanent guide pin primarily used to maintain alignment between cavities in two halves die.
Eject
It is the process of pushing the hardened casting out of the die.
Gooseneck Machine
It is also known as Hot-Chamber Machine. It is mainly used with zinc, tin and lead-based alloys.
Hot Short
It is a term used to describe an die cast alloy which lacks ductility or has a tendency to become brittle at elevated temperatures. Materials of such characteristics do not have enough tensile strength to resist stresses resulting from cooling.
Intergranular Corrosion
It is a type of corrosion characterized by cracking along grain boundaries of metals or alloys upon exertion of tensile stress. Local difference in the composition common in alloy castings is often the cause of this circumstance.
Shot Blasting
It is a process of cleaning metal where a fluid blast off abrasive steel balls against the surface for a clear finish.
Shut-Off
It is a point where the surfaces of the two halves die are fitted together to stop the flow of liquefied metal between them.
Sprue
It is a hole in a die casting tooling in a hot-chamber die casting machine which is the primary entry point of molten metals towards the chamber.
Like
Kinetic Die Casting Company on FaceBook
This is the blog on the Kinetic Die Casting Company web site. We are an American Die Casting Company. Look at this website page for more details: www.kineticdiecasting.com/american_die_casting.html. Contact Kinetic Die Casting Company at 818-982-9200 or email us at sales@kineticdc.com. Use this webpage to request “die casting part prices” www.kineticdiecasting.com/replyform.html
What is a Die Casting Draft Angle and Why is it Important?
What is a Die Casting Draft Angle and Why is it Important? Hundred million tons of metal products, precision metals and metal parts are produced each year. The aluminum die casting industries contribute a massive volume of these metals through the application of advanced technologies and methodologies. This includes giving importance to applying the right Die Casting Draft Angle in producing optimum quality and high volume metals parts.
Draft Angle is an important requirement in the die casting process. It is described as an angle or amount of slope that is incorporated into a wall of a die casting mold making the opening of the die cavity wider than its base. It is also known as the draft.
Die casting molds with surfaces perpendicular to the direction of ejection can damage the product and the mold. The metal formed will stick to the mold and an ejection by force and pressure causing an immeasurable damage. Additional cost will be incurred to produce another mold if it is reusable. Hence, a small angle must be applied I all surfaces.
During the cooling process, the castings will shrink towards the core at an acceptable rate. This is the reason why drafts are higher on the inner surfaces of the die. To avoid high pressure in castings, the inside corners must be protected with fillets.
The die cast Draft Angle requirement varies with the specific surface, the depth of the surface and the kind of alloy used in casting. To facilitate the ejection of die castings, the surfaces of the angle must be specified.
Because of the importance of Draft Angles in in aluminum die casting, Die Casting Manufacturing Companies employ specialists to give due consideration to such dimensional factors.
Like
Kinetic Die Casting Company on FaceBook
This is the blog on the Kinetic Die Casting Company web site. Using high pressure die casting and explains: What is Die Casting?. Look at this website page for more details: www.kineticdiecasting.com/what-is-die-casting.html. Contact Kinetic Die Casting Company at 818-982-9200 or email us at sales@kineticdc.com. Use this webpage to request “die casting part prices” www.kineticdiecasting.com/replyform.html
Classification of Porosity in Die Castings
Classification of Porosity in Die Castings. Porosity in casting aluminum alloys directly affects the reliability and quality of products which incorporating die cast metals into their design. Die Casting Manufacturing companies rely on advanced technologies and methodologies to minimize porosity so as to avoid additional overhead.
The types of porosity in die castings vary in terms of their characteristics. The three basic classifications however are continuous, blind and totally enclosed, which are manifested in four general types namely micro, micro/macro, funnel and macro.
Continuous Porosity
The first instance of continuous porosity in metal castings is the presence of leak path from a particular enclosed section towards another. The Micro Manifestation shows a slow single-point leak.
The second instance of continuous porosity is the presence of collective defects which are interconnected in many areas. The Micro/Macro Manifestation of such characteristic is multiple leak points at a slow rate.
The third instance of continuous porosity is the presence of externally visible defects with micro-sectional defects. The Funnel Manifestation is a slow single-point leak.
The fourth instance of continuous porosity is the gross visible defects in the surface of metal castings, shows extreme leaking in the Macro level.
Blind Porosity
The first circumstance is the absence of visible defects on the surface of die cast metals while micro manifestation displays a weeping of contaminants towards the surface. A wet or darkened region is also visible. On the other hand, the said casting holds pressure.
The second circumstance is the absence of visible imperfections on the surface. There are however darkened parts of the casting surface. The Micro/Macro Manifestations include gushing of machining fluid towards the surface. The castings on this instance still hold pressure.
The third circumstance is the visible die cast porosity and pitting on the surface. The Funnel Manifestation includes discoloration of the surface and weeping of machining liquids.
The fourth circumstance of blind porosity is the display of visible porosity holes on the surface of the metals and the roughness of the said surface. The Macro Manifestation includes surface discoloration and the presence of contaminants.
Totally Enclosed Porosity
Defects and impurities are not visible on the surface which is often caused by material shrinkage or gas accumulation. Shrink porosity is characterized by irregular shape and rough surface. Gas porosity is displays a smooth and regular shaped castings.
Like
Kinetic Die Casting Company on FaceBook
This is the blog on the Kinetic Die Casting Company web site. Rsing the die casting process and discusses Die Casting Military Parts. Look at this website page for more details: www.kineticdiecasting.com/military_parts.html. Contact Kinetic Die Casting Company at 818-982-9200 or email us at sales@kineticdc.com. Use this webpage to request “die casting part prices” www.kineticdiecasting.com/replyform.html
