Die Casting

Meet Reliable Die Casting Manufacturers With DiscoverSourcing.com

As a die casting products manufacturing sourcing solutions company in China, Discover Sourcing Limited helps oversea customers to get the high-quality die-casting products from China Manufacturers. In all the manufacturers we introduced, they maintain high quality standard to ensure products have consistency quality and meet the requirement of reliability and provide cost savings. 

Discover Sourcing and suppliers serve all of your die casting needs including:

  • Design of the tool;
  • Product design for manufacturing assistance;
  • Tightly controlled melting and metal care;
  • Repeatable and controlled machinery and processes;
  • Machining, finishing and sub assemblies.
  • Aluminum alloy, Zinc alloy, Magnesium alloy, Copper alloy, Lead and Tin alloy.

die casting

Die Casting For A Wide Variety of Industries.

We provide products or manufacturers sourcing services for all kinds of die castings in a wide range of industrial applications including:

  • Automotive industry: Some of our verified manufacturers are ISO 9001:2008 certified & ISO/TS 16949:2009. Auto parts for after market or refitting market, such as throttle body, front cover, pump cover, crankcase, oil pump cover, oil pan, camsaft bracket, Cylinder head cover, timing chain cover, bracket, fuel bowl, alternator bracket, rack & pinion housing, extension housing, clutch piston, transfer case RF/ RR, end cover/ Rear cover, foot pedal, alternator housing.
  • Medical: Our die casting suppliers can perform high-quality die casting for medical device customers. Our expertise encompasses essential medical products such as hospital bed gearboxes, surgical instruments, peristaltic pump pumps and hospital equipment.
  • Lighting: Some of our manufacturers are the leading die casting manufacturers when they come to the manufacturing of outdoor lighting products ( such as walk light housings, bullet light fixtures, coach lights and wall sconce fixtures) and housings for street and traffic light enclosures, LED Lights boxes and aluminum light enclosures.
  • Industrial Equipment: Components for compressor , piston connecting rods, motor housing, porter cable pump housings, wall mount bearing housings, industrial pumps parts, air compressors, locks, bracket for industrial equipment, power tool cover or housing, sanitary fittings and heat sink and many others.
  • Telecom Equipment: Our vendors are accomplished die casting manufacturer for telecom industry products such as electrical housings, mobile phone shell, connecting front face plates, antenna mounts and RF filters.
  • Toys: Any toy or collectible model produced by using the die casting method.

Why Choose Sourcing Services Company Discover Sourcing ?

  1. We or vendors offer engineering support, custom tool design and fabrication, finishing ( such as powder coating, painting, plating and anodizing, etc) and CNC machining for your short and long run requirements.
  2. Die casting for wide range of weight, we always could find the right suppliers for you.
  3. Purchase order control, quality control and Supply chain control for every process. our team inspects sample or products during manufacturing and before shipment to ensure that the parts meet the prints and quality standards you require.
  4. Our suppliers hold their parts to the high standards for strictly in tolerance.
  5. We help you to start your business with Low MOQ or small volume. Outsource services made outsourcing to China easy.

Quality Systems For Die Casting

In order to maintaining high quality standards, our suppliers use a lot of advanced methods to automate the die casting process and provide continuous quality control. The system obtains metal velocity, shot rod position, hydraulic pressure and other data that is used to adjust the die casting machine process, assuring consistent castings shot after shot. These process control systems also can collect die casting machine performance data for statistical analysis in quality control. This system together with PFMEA help reduce  and prevent die casting defect before they occur.

Die Casting Quality Problems and Solutions

Quality control in die casting is an extensive process. Like other products manufactured, such as stamping and forging parts, lots of problems that may happen during the manufacturing process, the quality control works must be customized to the needs of different products. There are a lot of  failing modes during the die casting process which must be prevented and avoided.

10 typical problems  or issues for aluminum die casting products.

  • Porosity (flow porosity, gas porosity and shrink porosity) opened up after machining creating leak paths.
  • Flash issue is that it forms a thin sheet of metal at the parting faces after casting process.
  • Trimming problem is that there is unwanted or excess  material on the casting parts.
  • Blisters issue is caused by gas becoming trapped inside the casting at the time the cavity is filled.
  • Cracks issue appears in die castings.
  • Appearance issues due to fill problems or die condition.
  • Surface defects which can occur during the casting and is hard to control.
  • Dimensional problems in the casting due to shifts, wear or moves in moving components in the die.
  • Leaking castings due to some combination of other issues.
  • Missed or improper secondary operations, such as machining, painting or assembly.

1, Porosity Issue

Porosity issue in die casting is really a main problem for die casting engineers all over the world which leads to a host of defects ranging from poor surface finishes to critical failures of pressure-tight components.

  1. GAS POROSITY – Usually internal, caused by trapped gases of various kinds in the die.
  2. SHRINK POROSITY – Caused by the change in volume as the metal changes state from liquid to solid.
  3. FLOW POROSITY – Caused by poor pressure or metal flow conditions in the casting process, result in surface or internal defects.

Die casting porosity can be discovered by using X-ray techniques. This is often effective in determining total porosity amounts, but it is difficult to determine specific location of small voids. And Destructive machining is also an effective way to evaluate porosity, but can be costly and may give inaccurate predictions based on sample sizes. The best methods for controlling porosity is via control of the die casting process itself to improve.

2, Flash Issue

Flash can be described as any unwanted or unneeded and excess casting metal which comes out of the die attached to the Cavities.

Some of the causes of flash issue are:

  • Die faces and die components damage.
  • Cavities offset from centre of platen.
  • Bending, crowning of stretching of dies.
  • Incorrect intensification timing.
  • Pressure spikes at the end of cavity fill.
  • Insufficient machine clamp-up.
  • Parts of the die has insufficient strength.
  • Excessive intensification pressure.
  • Wear or Damage, in toggle mechanisms.
  • Hydraulic valve or seal leaks.
  • Machine hydraulic malfunction.
  • Hydraulic valve or seal leaks.

3, Trimming Problems

Trim problems can have many causes, depending on the equipment and how to remove flash from die casting products. Tooling related issues can usually be avoided with a right maintenance routine and a good trim die design.

Detecting trim related issues is often difficult as it is usually a visual inspection. In line gaging or poke-yoke devices can be used for high severity problems.

4, Blisters Issue

Blisters show up as a swelling on the surface of the die casting, typically 1 ~ 20 mm in diameter and 0.5 ~ 5 mm in height. If they appear on a visible surface of the casting, they almost always have to be rejected. They cannot be re-worked or recovered and the only action is to remelt them. Blisters are caused by gas becoming trapped inside the casting at the time the cavity is filled. The most likely source of the gas is the air which was initially present in the cavity, runners and shot sleeve. When the plunger comes to the end of its stroke, it compresses the metal, and any gas trapped inside it, to a very high pressure — typically 20 to 70 MPa. This causes the gas to be compressed to very small bubbles, trapped inside the casting at high pressure.

Blisters form in two main circumstances.

Ejection: If the casting has very thin wall sections, the die surface temperature is very high and the casting is still very hot, then blisters can form soon after ejection. This is because the strength of the metal alloy surrounding the blister is very low at elevated temperatures. The pressure in the trapped gas is therefore able to force the surface skin apart and blow it up like a balloon.

Secondary Heating: Blisters can appear when castings are subsequently heated up in a secondary process such as Powder coating, Baking, Heat treatment, Testing, Welding. The secondary heating reduces the tensile strength of the alloy and the energy stored in the trapped gas enables it to expand, creating a blister on the surface of the casting.

5, Cracks Issue

Cracks can appear in die castings from a number of causes. Some cracks are very obvious and can easily be seen with the naked eye. Other cracks are very difficult to see without magnification.

Cracks on die casting parts can be caused by:

  • Shrinkage of the casting within the die.
  • Undercuts or damage in die cavities.
  • Uneven, or excessive, ejection forces.
  • Thermal imbalance in the die.
  • Insufficient draft in sections of the die.
  • Excessive porosity in critical regions of the part.
  • Product design not matched to the process.
  • Inadequate die design.
  • Lubrication problems.

6, Appearance Issues

Appearance issues can be detected visually, which is a cheap, but often unreliable method for detection. Vision systems haven’t been used extensively yet for this type of problem due to its variable nature.

As with most failure modes, the best method for preventing a problem from getting to the customer is to prevent them from occurring in the first place. To that end, process controls in place to maintain a robust process are key. Beyond that, tooling maintenance programs with agreements with customers are the best way to maintain tooling condition.

7, Surface Defects

Although cold flow is a very common surface defect on die cast parts, there are a variety of other surface defects which can occur and are sometimes difficult to eradicate. These include:

  • Staining from die spray or lubricants.
  • Sinks.
  • Surface micro-porosity.
  • Waves and Lakes.
  • Flux inclusions.
  • Drag marks.
  • Soldering.
  • Gate edge porosity.
  • Die erosion.
  • Carbon build-up.
  • Metal inclusions.
  • Laminations.

Furthermore, it is quite common for more than one type of defect to be present in the same casting. To accurately diagnose these types of defects, it is usually necessary to examine the part carefully under magnification.

Sometimes further chemical and analytical testing is required.

8, Dimensional Problems

Dimensional problems can be detected with either in line or off line gaging. Frequency of inspection is set up based on severity of potential problems and process stability.

Poke-yoke systems are usually effective in preventing dimensional problems from being passed on, when their implementation is feasible. Dimensional problems in castings are usually the result of tooling issues. Corrective actions to reduce or eliminate these problems are sometimes expensive, but are usually solid long term fixes to prevent recurrence.

9, Leaking Castings Issue

Like sand casting products, die castings usually leak for one of the above problems. Either porosity or surface issues in the parts create leak paths from the inside to the outside of a casting. Preventing the existence of these defects is an effort in process control.

Detecting leaking castings is usually done with an air decay leak tester. The advantage of air decay testing is its relatively quick test cycle. For die castings that have zero leak requirements, air decay testing may not be appropriate.

10, Secondary Operations Issues

New workers or miss understand the drawing or specs always make it a mistake on secondary operations process. We can double confirm with vendors before the die casting parts going to secondary operations process.

Process Failure Modes and Effects Analysis (PFMEA) is an effective tool for determining where a process needs control and inspection steps. Excess or unnecessary quality steps is a waste of resources while an uncontrolled process is a customer problem in waiting. An experienced die casting operator will balance these needs in setting up the part production process.

Die Casting Process Failure Mode and Effect Analysis (PFMEA)

ProcessFunction Requirement Potential Failure Mode Potential Failure Effect(s) Potential Failure Cause or Reason Current Process Control or Detection
Mat’l incoming Inspection wrong mat’l type product scrap,
customer complaint
suppliuer quality out of
1, Supplier provide mat’l report
2, Analyze mat’l content for every lot of mat’l
Mat’l Stock:
no mix of different type of raw mat’l
mix of different type of raw mat’l may have effec on product;
customer complaint
mat’l pile up not in order; label not clear 1, “color” control
2, Label the time & date
Mat’l fusion there’s rinsing in alum soup air vent on product there’s rinsing in raw mat’l and old mat’l 1, Add 0.2% chemical to remove rinsing and it record;
2, new mat’l: old mat’ rate, and its record.
NG mat’l type product disabled customer complaint mix mat’l during fusion “color” control, mat’l record, anylyze mat’l content by spectrum
furnace failure repair furnace furnace temperature not in reason furnace control
no mat’l absent, no air hole in appearance;
ejector depth within tolerance;
casting dimensions being steady
mat’l absent Scrap low temperature of inner mold 1, operator check & record, 1/1h
2, inspector check & record, 1/4h
low pressure & speed of injection 1, operator check & record, 1/1h
2, inspector check & record, 1/4h
abrasion of mat’l pipe operator check before each shift
low temperature of metal soup operator check before each shift
mold design not in reason incoming inspection of mold
die sticking deformation Scrap high temperature of inner mold 1, operator check & record, 1/1h
2, inspector check & record, 1/4h
draft angle too small confirm duiring FA procedure
black spot  inside part affect product appearance unloading chemical too much operator confirm
air bubble or air vent May have effect on product;
Customer complaint;
high temperature of
inner mold
1, operator check & record, 1/1h
2, inspector check & record, 1/4h
abrasion of mat’l pipe operator check himselt
high temperature of metal soup 1, operator check & record, 1/1h
2, inspector check & record, 1/4h
low-speed too high confirm low-speed before operation
inspector check & record, 1/4h
die land error Scrap mold design not in reason incoming inspection of mold
shrink holes Scrap mold design not in reason incoming inspection of mold
cooling system not in reason operator check
mold surface corrade Special treatment after casting wash out mold surface by metal soup operator check
ejector pin too deep Affect product appearance ejector pin too long check ejector pin length before loading mold
dimensions out of spec May have effec on product;
Customer complaint;
mold dimensions out of spec incoming inspection of mold
mold period is not proper inspector check, 1pc/4h
no burrs,
no scratch
burrs around pin or insert not remove clear Affect product appearance missing operation
by employees
1, operator check, 100%
2, inspector check, 5pcs/2h
scratch on product Scrap or Rework careless operation 1, operator check, 100%
2, inspector check, 5pcs/2h
Polishing glossy,
no scratch ,
no burrs
not glossy enough Affect product appearance too much product polish together 1, operator check, 100%
2, inspector check, 5pcs/2h
3. rework again
burrs around pin or insert not remove clear Affect product appearance heavy operation 1, operator check, 100%
2, inspector check, 5pcs/2h
scratch on product Scrap or Rework heavy operation 1, operator check, 100%
2, inspector check, 5pcs/2h
Cleaning & Package not clean enough Customer complaint wrong operation 1, operator check, 1pc/1h
2, inspector check, 1pc/2h
damage package Customer complaint packing 1, operator check, 1pc/1h
2, inspector check, 1pc/2h
Storage carton drops Scrap or Rework not following instructions when delivery 1, inspector: 100% inspection
2, inspector: 1pc/4H
forklift hit not following instructions when delivery 1, inspector: 100% inspection
2, inspector: 1pc/4H