Precision die casting is a precision manufacturing process that pours or injects molten metals into steel molds, compressed sand, or other materials.
This guide explores various aspects surrounding precision die casting by elaborating on commonly asked questions regarding this process.
Hence, ultimately, you’ll learn and understand the several aspects of this part-making process to assist you in future decision-making.
- What Is The Suitable Wall Thickness For Precision Die Casting?
- What Types Of Metals Are Used In Precision Die Casting?
- What Are The Steps Involved In Precision Die Casting Process?
- What Are The Types Of Dies Used In Precision Die Casting?
- What Are The Advantages Of Precision Die Casting?
- What Are The Main Variants In Precision Die Casting?
- What Are The Key Geometric Features In Precision Die Casting Design?
- Can Precision Die Casting Be Automated?
- What Types Of Machines Are Used In Precision Die Casting?
- How Is Precision Die Casting Different From Other Operation Processes?
- What Is The Minimum Order Quantity For Precision Die Casting Parts?
- What Is The Ideal Tolerance For Precision Die Casting?
- What Are The Benefits Of Using Thin-Walled Precision Die Castings?
- What Are The Characteristics Of Precision Die Casting Parts?
- How Do You Determine Cost-Effectiveness Of Precision Die Casting?
- Can Precision Die Casting Enhance Part Weldability?
- What Are The Disadvantages Of Precision Die Casting?
- What Are The Suitable Surface Finishing Options To Consider After Precision Die Casting?
- How Do You Determine The Quality Of Precision Die Casting Parts?
- What Are The Common Applications Of Die Casting?
- How Long Does It Take To Accomplish Precision Die Casting?
- How Durable Are Precision Die Casting Parts?
What Is The Suitable Wall Thickness For Precision Die Casting?
Precision die casting parts
Technically, there is no definite ideal wall thickness for a precision die casting component.
Instead, it is exceedingly fundamental to maintain a consistent wall thickness and possibly reduce weight to get a substantial cost-effective part.
Thus, the most suitable approach to attain this is by designing optimized gate and overflow locations into the part design.
It is vital in essential in avoiding unnecessary porosity and maintaining strength.
Simply put, the ideal wall thickness for die casting parts is based on the actual required dimensions of application.
What Types Of Metals Are Used In Precision Die Casting?
You can use several metals in precision die casting process.
However, the actual metal you are using is dependent on its ultimate use.
Ideally, it implies that different applications require metals with different properties to guarantee efficiency and reliability.
Hence, metals for precision die casting must maintain respective properties during and after melting and molding process.
The commonly used metals in this process include the following;
It is relatively economical since it takes little energy to melt.
Aluminum is also lightweight and exhibits rust and corrosion resistance with immense strength and dimensional stability at elevated temperatures.
Moreover, this metal is durable and accepts several surfaces finishes.
But its main shortcoming is that it is likely to experience shrinkage during cooling process.
Die cast aluminum parts
It is arguably among the best but overlooked precision die casting metal alloy since it provides immense versatility.
Zinc is relatively heavier than aluminum as it weighs almost 2-3 times more.
It implies aluminum is often used in place of zinc, where larger precision die castings are necessarily based on material cost and weight.
This metal is the easiest to cast, exhibits high ductility impact strength, and is easy to plat.
It is alloyed with several metals, which enhances its strength hence has higher impact resistance than cast aluminum.
Besides, zinc parts offer close tolerances with low casting temperatures leading to minimal thermal shock.
However, zinc often portrays a few issues in die casting process, such as porosity, burn cold, shrinkage, and flow mark among others.
Die cast zinc parts
Brass Die Casting
It is resistant to temperature changes and corrosion and exhibits high conductivity.
The melting point of brass is about 900° C; hence needs less energy to process it.
You can quickly form parts in bulk using brass material.
But a major shortcoming of brass is that melting it can be challenging thus likely to complicate precision die casting process.
Scaling and porosity are also common with brass during this process.
Die cast brass part
Other metals used in precision die casting process include the following;
- Stainless steel
- Carbon steel
What Are The Steps Involved In Precision Die Casting Process?
Precision die casting process often varies depending on the actual method and equipment you are using.
However, high-pressure die casting process is often used by many manufacturers, and here is its basic step-by-step process;
It involves spraying the die with a lubricant or a recommended releasing agent.
Generally, lubricants are essential in cleaning part release by putting a film over the part.
Lubricating agent is mixed with water, which evaporates upon spraying on heated steel die.
Both die halves are clamped under high pressure, but the machine determines the ideal amount of force.
The amount of cooling time is dependent on actual type of metal you are die casting.
Often, different metals usually solidify at different temperature ranges.
Besides, the part geometry and desired wall thickness also play a determinant role in cooling time.
This step involves separating the halves of the mold with an ejection mechanism forcing out the part out of the die.
Notably, it is imperative to prudently monitor the amount of force for removal.
It starts with deflashing, which involves removing a thin metal portion around casting edge.
Primarily, during casting process, excess metal material may have seeped between the runners or die halves, thus the need for removing it.
What Are The Types Of Dies Used In Precision Die Casting?
Types of die casting in precision die casting are often categorized as follows;
Single-cavity die – It is used in producing one component
Multiple cavity dies – Used for producing a wide range of identical components
Combination die – You use this die to produce numerous parts for an assembly
Unit die – For simultaneous production of different simple parts
What Are The Advantages Of Precision Die Casting?
The main benefits of precision casting method include the following;
Increased Production Efficiency
Tools and equipment used in precision die casting are fast and reliable, thus guaranteeing high productivity.
For instance, a cold air die casting machine has an average capacity of die-casting up to 700 times in eight hours.
On the other hand, a small hot-chamber die casting machine can produce up to 7,000 times in eight hours.
As such, you are guaranteed high production volume, which is essential in increasing turnover and profitability.
Immaculate Product Quality
Precision die castings exhibit high dimensional accuracy, which offers a good surface finish.
Precise dimensions of these casting parts make the surface material immensely smooth.
Therefore, you’ll no longer need to use mechanical processing to enhance the surface finish.
Besides, you can produce casting parts in bulk within shortest time using this process.
All these imply that you’ll reduce your costs significantly, which is essential from a commercial perspective.
Easy To Produce Complex Parts
Precision die casting enables you to create parts with complex shapes, which you cannot necessarily attain using other part-making processes.
Improves Strength And Reduces Weight
This casting process produces comparatively thin-walled components with reduced weight and augmented strength.
What Are The Main Variants In Precision Die Casting?
During precision die casting operation, several deformities, flaws, and errors are usually common.
Of course, the severity of these issues would depend on the type of metal you are casting and the actual method you are using.
However, several variants such as the following can help to overcome such issues during precision die casting operation;
Before injecting or pouring molten metal, it is essential to fill the die cavity with oxygen.
When semi-liquid metal enters the cavity, it combines chemically with oxygen to inhibit gas bubbles, thus eliminating trapped gas pores.
It is an anagram for precision, reliability, and density.
Ideally, this variant combines stable fill and directional solidification for faster cycle times.
Some of its aspects include thermal analysis, heat treatable castings, indirect squeezing, and flow and fill modeling.
When the shot is partly solidified, double pistons increase the pressure.
When molten metal is poured wholly and directly fills the die hence forms turbulence and oxidation.
Usually, the die could be vertical, horizontal, or tilted, but the operation yields parts featuring strength, high quality, mechanical properties, and stiffness.
It is a labor-intensive process, which involves shaping the mold from a wax prototype dipped in liquid ceramic.
As ceramic hardens, the wax melts away, and molten metal is poured into ceramic cavity.
Once it solidifies, ceramic mold breaks away, and metal casting is removed.
Vacuum-assisted High Pressure
This precision die casting variant entails placing die in airtight housing.
Consequently, it creates pressure in the die cavity drawing molten metal to solidify before ejecting it.
What Are The Key Geometric Features In Precision Die Casting Design?
Ordinarily, it is the precision die casting geometry that determines how parts cool and fill.
It also affects porosity, grain, and stress of the part.
Even so, the grain structure stress levels are often dependent on the type of metal.
The primary geometric features in this operation include the following;
It strengthens the component by redirecting stress concentration at sharp interior edges.
Ideally, this geometric feature distributes stress concentration over the fillet’s broader volume to reduce weak points.
Moreover, it inhibits cracking during part straightening.
These are mounting points and stand-offs and are often designed to maintain consistent wall thicknesses.
It is an angle that varies based on various aspects of the metal, such as surface depth and wall surface.
This is the point where two die halves meet.
Essentially, it defines the interior and exterior surfaces and the specific side of a die’s cover and injector.
They help the molten metal to fill all components of precision die casting.
Besides, ribs provide a path for molten metal and streamline the speed up ejection.
Holes And Windows
These need the highest level of drafting because they connect with die surface.
Hence, this makes ejection quite tricky and likely to block molten metal flow.
Can Precision Die Casting Be Automated?
Most modern precision die casters use several complex techniques to automate this operation and provide excellent quality control.
You can use automated systems to lubricate dies and integrate other functions like quenching and trimming castings.
Precision die casting machines have microprocessors, which obtain metal velocity, hydraulic pressure, and shot rod position among other data, to adjust accordingly.
Thus, such data assure consistent casting shot after shot.
Moreover, these automated process control systems record machine performance data essential for statistical analysis in controlling quality.
What Types Of Machines Are Used In Precision Die Casting?
Precision die casting machines are available in different sizes and often vary based on the actual method of injecting molten metal into the die.
The commonly used equipment include the following;
Hot Chamber Machines
Hot chamber die casting
These machines are used specifically for low melting point alloys, which hardly attack or erode plungers, metal pots, and cylinders.
Hot chamber machines are hydraulically controlled and have automated cycling controls and safety features.
In this machine, the injection mechanism is immersed in melted metal inside a furnace attached to the equipment.
Cold Chamber Machines
Cold chamber die casting
The cylinder and injection plunger in this machine is hardly submerged in molten metal, unlike hot chamber machines.
Instead, it is poured into a cold chamber through a pouring slot or port hand, or automatic ladle.
Its hydraulically operated plunger advances forward and seals the port to force molten metal into locked die at high pressures.
In this machine, more molten metal is poured into chamber than is required to fill the die cavity.
Essentially, it helps to sustain enough pressure to pack the cavity solidly with casting alloy.
How Is Precision Die Casting Different From Other Operation Processes?
It varies from other casting processes depending on several factors. Some comparisons include the following;
Precision Die Casting Vs. Plastic Injection
Essentially, plastic injection molded components are more flexible but less strong with weaker dimensional stability.
Besides, they take secondary surface finish like chrome plating better are often less resistant to heat, cracking, weathering, and UV rays.
However, plastic injection parts have ideal color versatility insulating and electrical properties.
Precision Die Casting Vs. Stamping
You can make stampings in steel, and unsuitable alloys for precision die castings.
These stampings are easier and faster to produce and more lightweight than precision die castings.
However, a single casting can replace numerous parts, unlike die castings, which often require fewer assembly operations.
Precision Die Casting Vs. Forging
Notably, forged parts tend to be stronger and denser than precision die castings and can easily be produced in ferrous and other metals.
On the other hand, die casting parts can be relatively complex and have shapes you can hardly forge.
They also have thinner walls, and you can hold them to closer dimensions than forged parts.
Precision Die Casting Vs. Sand Casting
Typically, sand cast parts need more machining and have thicker walls and less dimension precision than precision die castings.
However, sand casting offers lower tooling costs and is produced faster than precision die castings.
What Is The Minimum Order Quantity For Precision Die Casting Parts?
It varies significantly based on the specific manufacturer you are purchasing from.
Most manufacturers have a set MOQ limit based on different aspects surrounding the specific parts.
However, you can always negotiate and agree on a particular MOQ depending on your demands.
Of course, many manufacturers offer flexible MOQ due to specialty in short run.
Thus, there is no definite MOQ when buying precision die castings.
What Is The Ideal Tolerance For Precision Die Casting?
It is dependent on numerous factors, especially the type of metal you are casting and the specific application of the resultant part.
Ideally, it vital for design engineers to understand the particular precisions required for each part.
Simply put, precision tolerances should be outlined in agreed-upon critical areas.
What Are The Benefits Of Using Thin-Walled Precision Die Castings?
Ordinarily, thin-walled precision die casting parts are beneficial in several ways as follows;
- Guarantees unmatched versatility since you can easily use it in a broad range of applications.
- Makes it easy for you to create different surface finishing options suitable for various applications.
- They are generally lightweight, which is a crucial aspect in tooling, particularly in handling the part effectively in different applications.
- Thin-walled parts retain exact dimensional stability making the particular applications reliable and effective.
What Are The Characteristics Of Precision Die Casting Parts?
Precision die cast components
Generally, the actual features of precision die castings depend on casting method and the specific metal used.
In essence, it implies that different precision die-castings can be quite unique and demonstrate various characteristics.
However, here are the main characteristics you will always find in a wide range of these parts
- Relatively lightweight
- Exceptional hardness and tensile strength
- High thermal conductivity
- Smooth quality finish
- Thin wall capability
- Better electrical conductivity
- High accuracy and dimensional stability
How Do You Determine Cost-Effectiveness Of Precision Die Casting?
Notably, cost-effectiveness of precision die casting is determined on a case-by-case basis.
In some instances, it can be expensive to convert to precision die casting from other operations such as screw machining and stamping.
Even so, the most appropriate way to establish the cost is by inquiring from the design engineer whether conversion would be more economical.
Can Precision Die Casting Enhance Part Weldability?
Of course, part weldability is technically limited to metals.
However, it is easier to achieve weldability in some metals than in others.
It means part weldability is principally based on microstructure and mechanical properties of the part.
Thus, precision die casting enhances the part’s microstructure, ultimately improving its integrity.
Essentially, this improves part weldability without ideally using costly materials to seek higher weldability.
What Are The Disadvantages Of Precision Die Casting?
They are quite a few, but the major ones include the following;
- It can be relatively costly since it needs to be individually precision manufactured. This often requires several hours of crafting, shaping, and forming.
- The molding and shaping equipment is precisely designed to endure heating process and stress.
- It is only more efficient when using metals with high fluidity, which influence specific parts produced.
- The process needs close monitoring and management, particularly at the cooling phase.
What Are The Suitable Surface Finishing Options To Consider After Precision Die Casting?
You can incorporate a wide range of surface finishing options in precision die castings, but the major ones include the following;
- Mechanical finish – Common mechanical finish operations include sandblasting, polishing, abrasive blasting, grinding, etc.
- Chemical finish – It is a surface finish achieved by altering chemical composition of a metal part by using specific chemical substances.
- Anodized finish – This process involves using electrochemical elements to convert part surface into a decorative, durable, rust-resistant anodic oxide finish.
- Powder coated finish – It is a surface coating method that uses dry powder through an electrostatic process.
How Do You Determine The Quality Of Precision Die Casting Parts?
Often, precision die casting parts usually undergo rigorous tests to determine their quality.
Generally, here are the notable quality test for such castings;
- Preliminary test – It entails scrutinizing the component to determine whether they are appropriately filled with respective metals.
- Mechanical test – This tests whether cast parts possess suitable characteristics.
- Dimensional test – It seeks to determine a particular value range the precision die casting part falls in.
- Chemical test – The essence of this test is to analyze chemical properties of precision die castings and ensure they are within required levels.
- Non-destructive test – It determines part’s quality without destroying it.
What Are The Common Applications Of Die Casting?
Precision die castings are largely used in different industries to make various products and components.
The common applications, nonetheless, include the following;
- Medical field
- Automotive parts
- Aircraft parts
- Consumer electronics
- Telecommunication equipment
- Hand and power tools
- Lighting fixture
How Long Does It Take To Accomplish Precision Die Casting?
The turnaround for completing precision die casting operation is dependent on various factors such as the following;
Type of metal – Different metals have various properties, which often determine the actual casting lead time.
Casting method and equipment – Your casting method between hot and cold chamber influence the turnaround time.
Part complexity – Often, casting relatively complex parts may take longer since it involves higher intensity, unlike simple parts.
Parts quantity – Casting a few parts would take a shorter period than high volume parts.
Type of die – Precision die casting using unit die guarantees faster production turnaround since it can produce several part designs simultaneously.
Hence, there is no defined lead time for precision die casting. It depends on numerous factors, including the few mentioned.
How Durable Are Precision Die Casting Parts?
Naturally, the parts produced through precision die casting are strong.
They feature high tensile strength and other features that resist various unfavorable conditions.
Besides, the surface material of such parts is often reinforced using different coating techniques to enhance their resistance.
Hence, such parts can withstand aggressive conditions without necessarily wearing out.
In a nutshell, these parts can last for several years in different applications.
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