Selective Laser Sintering (SLS) is an additive manufacturing process that involves the use of a laser to selectively sinter (fuse) powdered material together to create a solid 3D object

The process begins with a digital 3D model of the object being created. A bed of powdered material, such as plastic, metal, or ceramic, is spread out over a build platform. A high-powered laser beam is then directed at specific points on the bed, heating and fusing the powder together to form a solid layer. The platform is then lowered, and a new layer of powder is spread over the previous layer, and the process is repeated until the entire object is formed.

The laser is controlled by a computer that follows the instructions in the 3D model, selectively sintering only the areas where the object is to be formed. The unsintered powder serves as a support structure for the object being created, allowing for the creation of complex shapes and geometries.

After the object has been fully sintered, it is removed from the build platform and excess powder is removed through a process called depowdering. The final product is a solid, fully functional 3D object that can be used in a variety of applications, including prototyping, product design, and production of end-use parts.

Pros:

• Versatility: SLS can work with a wide range of materials.
• Precision: SLS is capable of producing highly accurate and precise parts with intricate geometries and fine details.
• No need for support structures: SLS does not require support structures to hold up the part during printing, reducing waste and allowing for more complex geometries.
• High strength: SLS-produced parts are typically stronger and more durable than those produced using other 3D printing technologies.

Cons:

• Expensive: SLS machines are typically more expensive than other 3D printers, and the materials used can also be costly.
• Post-processing required: SLS-produced parts often require post-processing to remove excess powder and improve surface finish.
• Limited resolution: While SLS is capable of producing highly precise parts, the resolution is typically lower than that of other 3D printing technologies, such as stereolithography (SLA).

SLS is capable of producing highly accurate and precise parts, with tolerances typically in the range of 0.1-0.2 mm.

SLS-produced parts are typically stronger and more durable than those produced using other 3D printing technologies, due to the sintering process that fuses the material particles together.

More information and technical specification you see below in our inudstrial-grade 3D priting powders overview.

The maximum size of parts that can be produced using SLS depends on the size of the SLS machine being used. Some machines have build volumes of several cubic feet, while others are much smaller.

In the chart below you will find the build volume of each material we are able to print with our systems.

SLS machines are typically more expensive than other 3D printing technologies. The cost of SLS-produced parts depends on the material and size of the part. Complexity is mostly not a cost factor.

Most economical print jobs are those, you in need of larger quantities (smaller part) you able to fill up the maxiumum build volume. Here you can find a short video which illustrates this apporache well.

Tensile strength is a measure of the ability of a material to resist breaking under tension. It is the maximum stress that a material can withstand while being stretched or pulled before it breaks or fractures.

The maximum load is the highest amount of force that can be applied to a material before it fails. This load is usually expressed in units of Newtons (N) or pounds-force (lbf).

MPa (megapascal) is a unit of measurement for stress or pressure, commonly used in engineering and science. It represents one million pascals, which is a unit of pressure or stress. The pascal is defined as the pressure exerted by a force of one newton per square meter.

Tensile strength is usually expressed in units of MPa or psi (pounds per square inch). This measurement is obtained by dividing the maximum load that a material can withstand by its cross-sectional area. For example, if a material can withstand a maximum load of 10,000 N and its cross-sectional area is 0.01 square meters, then its tensile strength is 1,000,000 N/m2 or 1 MPa.

In summary, the tensile strength is the maximum stress a material can withstand before breaking when it is being stretched or pulled, and it is usually expressed in units of MPa or psi. The maximum load is the highest amount of force a material can withstand before failing, and it is usually expressed in units of Newtons or pounds-force.

Tensile modulus, also known as Young's modulus, is a measure of a material's stiffness or elasticity under tensile stress. It is defined as the ratio of stress to strain in the linear region of a stress-strain curve, where stress is the force per unit area applied to a material and strain is the ratio of the change in length to the original length of the material.

Mathematically, the tensile modulus can be expressed as: Tensile modulus (E) = Stress/Strain

The tensile modulus is measured in units of pressure or stress, such as pascals (Pa), newtons per square meter (N/m²), or pounds per square inch (psi). The higher the tensile modulus, the stiffer or less elastic the material is. For example, steel has a higher tensile modulus than rubber, which means that steel is less elastic and more rigid than rubber.

Tensile modulus is an important property for materials that are subjected to tensile loads, such as in bridges, buildings, and aircraft. It helps engineers and scientists to determine the ability of a material to resist deformation under tension and to design structures that can withstand the required loads.

Elongation at break is a measure of the ductility or stretchiness of a material, and it represents the percentage increase in length of a material before it breaks or fractures under tension. It is the maximum strain or deformation that a material can undergo before it fails.

Elongation at break is typically determined by tensile testing, which involves stretching a sample of the material until it breaks while measuring the change in length of the sample. The elongation at break is calculated as the percentage increase in length of the sample at the point of fracture compared to its original length.

For example, if a material has an original length of 100 mm and it stretches to 150 mm before breaking, the elongation at break is (150-100)/100 x 100% = 50%. This means that the material can undergo a 50% increase in length before it breaks under tension. Elongation at break is an important property for materials that are subject to high tensile stresses, such as plastics, rubbers, and textiles. It helps engineers and scientists to determine the ability of a material to withstand deformation under tension and to design products that can perform under the required loads.

In summary, elongation at break is the maximum deformation or stretch that a material can undergo before it breaks under tension, and it is expressed as a percentage increase in length of the material at the point of fracture.

Izod impact strength is a measure of the impact resistance of a material and is named after the British engineer Edwin Gilbert Izod. It is determined by measuring the amount of energy required to break a notched sample of the material under a high-velocity impact.

In the Izod impact test, a notched sample of the material is placed in a holder and then struck with a pendulum that swings down and hits the sample, causing it to fracture. The amount of energy required to fracture the sample is measured in Joules (J), and this value represents the Izod impact strength of the material. The notched sample is used in the Izod test to provide a pre-existing point of weakness or stress concentration, which simulates the effect of a notch or crack in the material that can weaken its overall strength. The notch allows the impact to focus on a small area of the material, making it more likely to fracture.

Izod impact strength is an important property for materials that are subject to impact or shock loads, such as plastics, metals, and composites. It helps engineers and scientists to determine the ability of a material to withstand impact forces and to design products that can withstand the required impact loads.

In summary, Izod impact strength (notched) is a measure of the amount of energy required to fracture a notched sample of a material under high-velocity impact. The notched sample is used to simulate the effect of a crack or notch in the material that can weaken its overall strength.

During SLS, a laser is used to selectively melt and fuse layers of powdered material to create a three-dimensional object. As the laser melts the powder, the unsintered powder in the build chamber becomes depleted. To ensure that there is always enough powder for the next layer, new powder must be added to the build chamber at a specific rate. This rate is known as the refresh rate.

The refresh rate can vary depending on the specific SLS system being used and the size and complexity of the part being printed. In general, a higher refresh rate can lead to faster printing speeds and better part quality, as it ensures that there is always enough fresh powder available for each layer. However, a higher refresh rate can also result in more powder waste, as unused powder must be removed from the build chamber and recycled or discarded.