Hardness: The critical parameter in 3D printing materials

In the field of 3D printing, the performance of materials directly affects the quality and application effect of printed parts. Among them, hardness, as an important mechanical performance index, measures the ability of materials to resist local deformation. Understanding and optimizing the hardness of 3D printing materials is crucial to ensure the strength, wear resistance and adaptability of printed parts in specific environments. This article will introduce the hardness index in 3D printing in detail and how to correctly evaluate this parameter when selecting materials.

Source: https://www.facebook.com/aon3dinc/posts/1402048853183073/?_rdr

What is hardness?

Hardness is a physical property that characterizes the ability of a material to resist indentation or scratching. It is usually measured by applying a certain force on the surface of the material and measuring its deformation depth or deformation area. In 3D printing, hardness not only affects the durability and wear resistance of the material, but may also affect its functional performance in different application scenarios.

How to measure the hardness of 3D printing materials?

The measurement method of hardness varies depending on the type of material. The following are several common hardness test methods:

1. Shore Hardness

This is a hardness test method used to measure soft materials (such as rubber and elastomers), which is divided into type A and type D. Shore A is mainly used to measure soft materials, while Shore D is used for harder plastic materials. In the field of 3D printing, Shore hardness is often used to evaluate the hardness of elastomeric materials such as TPU.

Ranking of the Best TPU Filaments According to Shore Hardness

Source: https://x3d.com.au/blogs/tips-and-tricks/ranking-of-the-best-tpu-filaments-according-to-shore-hardness

2. Rockwell Hardness

The Rockwell hardness test method is suitable for hard materials such as metals or hard engineering plastics. It evaluates the hardness of the material by measuring the depth of the indenter into the material surface. In metal 3D printing, Rockwell hardness is often used to measure the durability of metal parts.

3. Brinell Hardness

The Brinell hardness test is usually used for metal and alloy materials. It evaluates the hardness by pressing a steel ball into the material surface and measuring the indentation diameter. Brinell hardness is usually used in scenarios where the overall hardness over a large surface area needs to be evaluated.

Factors affecting the hardness of 3D printing materials

1. Material selection

Different 3D printing materials have different hardness ranges. For example, PLA, a common 3D printing material, has a high hardness, while elastomeric materials such as TPU are relatively soft. Metal materials such as aluminum alloy or stainless steel have higher hardness and are suitable for parts that require high strength and wear resistance.

2. Printing parameters

Printing parameters such as layer height, infill rate and printing temperature will also affect the hardness of the final part. High infill rate usually enhances the hardness of the printed part, while low infill rate may cause the printed part to be soft and brittle. In addition, the adjustment of printing temperature will also affect the molecular structure of the material, thereby affecting the hardness.

3. Post-processing method

Some post-processing methods such as heat treatment, coating or electroplating can also significantly improve the hardness of 3D printed parts. For example, after heat treatment of metal printed parts, their internal crystal structure will change, thereby improving hardness and durability. In the collaborative video of JLC3DP and Hacksmith Industries, the blogger used nanotechnology electroplating on the 3D printed clavicle model, and coated the surface of the material with a thin layer of metal to enhance the performance of the material, making the strength of the original resin material bone model significantly improved.

Source: https://www.youtube.com/@hacksmith

How to choose the right hardness material?

When choosing a material suitable for 3D printing, designers need to choose a material with suitable hardness according to specific application requirements. Here are a few factors to consider:

Application environment: If the part needs to be used in a high-wear, high-pressure environment, it will be more advantageous to choose a high-hardness material.

Flexibility requirements: If the design requires a certain degree of flexibility and elasticity, a material with a lower Shore hardness, such as TPU, should be selected.

Durability and strength: For parts that bear heavy objects or require high strength, such as metal parts, it will be more appropriate to choose a material with a high Rockwell or Brinell hardness.

Conclusion

In the field of 3D printing, hardness is an important performance indicator. It not only affects the structural strength and durability of the printed part, but also determines its adaptability in different application scenarios. By choosing the right hardness material, designers and engineers can optimize the performance of 3D printed parts to meet the needs of various industrial, medical and consumer product fields.

As a global leading 3D printing service provider, JLC3DP has a rich selection of printing materials. Whether you need high-hardness metal prints or flexible elastomer parts, we can provide customized printing solutions.