For electric wheelchair users, smooth and reliable movement is important.
At CEX Casting, we understand this need and are committed to improving mobility through precision engineering.
The roller guide, manufactured using our advanced squeeze casting process, proves our dedication to quality and performance.
Squeeze casting provides excellent precision and strength, making it highly suitable for manufacturing the roller guide used in electric wheelchairs. By using AlSi10Mg aluminum alloy+T5 heat treatment, ensuring high strength and defect-free products, enhancing the overall functionality and durability of the roller guide.
What Is the Roller Guide
The roller guide is a key component in electric wheelchairs.
It is a mechanism to make the wheel move smoothly and steadily by guiding the wheel moving on a fixed track, to provide users a comfortable and easy control.
The roller guide is made at CEX Casting by our advanced aluminum squeeze casting process.
What Are the Challenges in the Production of Roller Guide
Strength
The roller guide must be made of materials with sufficient strength to support the loads and stresses they will bear.
Choosing the appropriate aluminum alloy and ensuring its proper heat treatment is crucial for achieving the necessary mechanical properties.
Deformation
During the manufacturing of the roller guide, thermal expansion is a common occurrence, and if not managed properly, it can lead to deformation.
Post-production heat treatment is used to stabilize parts and release residual stresses.
However, improper heat treatment can lead to further deformation.
Proper control of the heat treatment process is critical to prevent these problems.
What Our Customers Expect from CEX
The story of the roller guide began with a customer-facing issue with their existing production method.
They were using A356 aluminum alloy with T6 heat treatment for producing the roller guide, but this led to significant deformation and a high rejection rate.
Seeking improvement, they turned to CEX for a solution.
Understanding the critical role of this component in wheelchairs, where both strength and stability are essential for safety, we recognized the challenge: the structure of this component causes itself to deform under T6 heat treatment.
To resolve this, we recommended switching to AlSi10Mg aluminum alloy and using a T5 heat treatment.
This adjustment preserved the required mechanical properties while eliminating deformation, ensuring both high performance and reliability.
Material Comparison
A356
Alloy Composition
● Silicon (Si): 6.5% – 7.5%
● Magnesium (Mg): 0.25% – 0.45%
● Copper (Cu): up to 0.2%
● Iron (Fe): up to 0.12%
● Manganese (Mn): up to 0.1%
● Zinc (Zn): up to 0.1%
● Others: the balance is aluminum (Al), with trace amounts of other elements such as titanium and chromium, generally kept to a minimum.
Mechanical Properties
● Tensile Strength: typically ranges from 250 MPa to 310 MPa.
● Yield Strength: generally around 170 MPa depending on the heat treatment.
● Elongation: typically 3% to 7%.
● Hardness: varies with heat treatment but generally falls between 60 to 90 HB.
AlSi10Mg
Alloy Composition
● Silicon (Si): 9.0% – 11.0%
● Magnesium (Mg): 0.3% – 0.6%
● Copper (Cu): Up to 0.2%
● Iron (Fe): Up to 0.2%
● Manganese (Mn): Up to 0.1%
● Zinc (Zn): Up to 0.1%
● Others: The balance is aluminum (Al), with trace amounts of other elements like nickel, titanium, and chromium, usually kept to a minimum.
Mechanical Properties
● Tensile Strength: typically ranges from 290 MPa to 350 MPa, depending on the heat treatment and casting conditions.
● Yield Strength: generally around 230 MPa to 290 MPa.
● Elongation: typically 5% to 7%.
● Hardness: usually falls between 70 to 90 HB.
T5 and T6 Heat Treatment Comparison
T5 Heat Treatment
Process
As-Cast State: the material cools naturally after casting.
Artificial Aging: the material is reheated to a temperature range of 160-180°C and held for several hours.
This process allows the alloying elements to form a precipitated phase, which increases the hardness and strength of the material.
Characteristics
● Usually, single-stage aging treatment is used without prior solution heat treatment.
● Mainly through precipitation hardening to improve hardness and tensile strength.
● Suitable for applications that require immediate hardening after casting without extensive heat treatment cycles.
T6 Heat Treatment
Process
Solution Heat Treatment: the material is heated to a high temperature, usually around 530-540°C, and held for a specified time to dissolve the alloying elements into the aluminum matrix.
Quenching: the material is cooled rapidly, usually by water quenching, to retain the alloying elements in a supersaturated solid solution.
Artificial Aging: after quenching, the material is reheated to a lower temperature, usually around 155 ° C, and held for several hours to form fine precipitate phases, significantly improving strength and hardness.
Characteristics
● Involves a more complex multi-stage process including solution heat treatment, quenching, and aging.
● Comes with higher tensile and yield strengths compared to T5, due to the combination of solid solution heat treatment and aging.
● Provides better mechanical properties, including better fatigue resistance and higher ductility.
It can be seen that the mechanical properties of T5 heat treatment are not as good as T6 heat treatment, but it can effectively avoid deformation, making it suitable for squeeze casting parts with complex structures that are prone to deformation when using T6 heat treatment.
The temperature of T6 heat treatment is higher, so it can obtain better mechanical properties than T5, which is suitable for parts that require high strength and are not easily deformed.
Mechanical Properties by CEX Squeeze Casting
Below are the mechanical property test results we did for A356-T6 and AlSi10Mg-T5 squeeze castings:
A356-T6
Mechanical Properties
● Tensile Strength: 280 MPa to 300 MPa.
● Yield Strength: 225 MPa to 240 MPa.
● Elongation: 8.5% to 14.5%.
● Hardness: 84.9 HB.
AlSi10Mg-T5
Mechanical Properties
● Tensile Strength: 295 MPa.
● Yield Strength: 225 MPa.
● Elongation: 10.5%.
● Hardness: 89.2 HB.
It can be seen that the mechanical properties of AlSi10Mg-T5 are similar to A356-T6, and T5 heat treatment can avoid deformation.
Therefore, for the roller guide, we have chosen to produce it using AlSi10Mg-T5 to avoid deformation problems without loss of mechanical properties.
Advantages of Squeeze Casting for Producing the Roller Guide
Ensuring Strength
The squeeze casting technology of CEX Casting ensures the strength of the roller guide.
By applying high pressure during the solidification process, porosity and other common casting defects can be eliminated.
This makes the microstructure denser and more uniform, providing excellent mechanical performance after heat treatment and ensuring the roller guide can withstand the harsh working conditions of electric wheelchairs.
High Yield and Efficiency
The squeeze casting process significantly improves productivity as deformation problems are solved.
The elimination of defects and guaranteed dimensional accuracy reduces the need for post-processing and rework.
As a result, our production line can achieve higher throughput and efficiently handle high-volume orders, ensuring that we can deliver high-quality roller guides promptly on a large scale.
Why Choose CEX Squeeze Casting
Patented Technology and Expertise
CEX Casting utilizes an optimized patented high-precision squeeze casting technology to manufacture the roller guide.
We optimize the inlet design to insulate the casting process from air.
We provide in-house mold design and making services with specially designed air venting channels.
Centralized melting equipment is used to ensure uniform alloy quality and precise temperature control.
These optimization measures ensure that every part we produce meets the highest quality and performance standards, providing our customers with reliable and effective solutions.
Strict Quality Control
We are a manufacturer certified by ISO 9001 and IATF 16949, strictly adhering to quality system standards throughout our production.
We are equipped with various quality inspection instruments, including CMM, X-ray machines, orient spectrometers, tensile testing machines, hardness testers, etc.
Each roller guide undergoes comprehensive testing and inspection to ensure reliability, safety, and the highest standard performance of each part.
Customer Service
At CEX Casting, we involve customers throughout the project with a dedicated team, including a sales manager, assistant, and product manager, for prompt feedback.
We prioritize customer satisfaction and conduct biannual surveys to gather insights for continuous improvement.
Our updates on production capabilities are shared through targeted emails and social media to keep customers informed and confident in our capabilities.
Conclusion
The roller guide produced by CEX Casting is a typical example of how advanced squeeze casting technology can improve component performance and reliability.
By utilizing AlSi10Mg aluminum alloy applied with T5 heat treatment, we ensure that each roller guide comes with excellent strength, durability, and precision.
Contact us for more information about our aluminum squeeze casting case studies or to discuss your project requirements.