Selective laser melting 3d printers:concepts,principles,applications

January 18, 2024

By Jeff wei

SLM (Selective Laser Melting) 3D printers are an advanced manufacturing technology that builds up layers of laser-melted metal powders to achieve high-precision and complex-structured metal part manufacturing. This technology is widely used in the industrial and professional sectors, enabling manufacturers to achieve rapid prototyping, small batch production and personalisation, with great benefits for businesses, from part performance to productivity gains.

What is Selective Laser Melting?

Selective Laser Melting (SLM) is an additive manufacturing (3D printing) technology that is a form of metal 3D printing. During selective laser melting, a high-energy laser beam is used to scan and melt metal powder layer by layer to gradually build complex three-dimensional metal parts.SLM is an advanced metal 3D printing technology that provides an efficient and accurate method for manufacturing complex metal parts. As materials and processes continue to improve, it is expected that SLM technology will be used in a wider range of fields and bring more innovation and growth opportunities to the manufacturing industry.

What is a Selective Laser Melting 3d Printer?

A Selective Laser Melting 3D printer is a 3D printing device that uses Selective Laser Melting (SLM) technology. It is a metal 3D printing technology that converts digital design files directly into metal parts.

A Selective Laser Melting 3D printer works on the same principle as Selective Laser Melting technology. It uses a high-energy laser beam to scan and melt metal powder to build metal parts layer by layer. Selective laser fusion 3d printers can build complex metal parts with high precision, good mechanical properties and material characteristics.

Selective Laser Melting 3D Printer
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How does selective laser fusion 3d printing work?

Selective Laser Melting (SLM) 3D printers work as follows:

  • Preparation: First, a build platform or table is prepared, usually a flat piece of metal. Then, a thin layer of metal powder is applied to the build platform, usually using a homogeneous method to spread the powder evenly.
  • Design File Preparation: The 3D model of the target object is converted to STL file format, which contains the geometry and structural information of the object.
  • Scanning and melting: Selective laser melting 3D printers use a high-energy laser beam to scan layers of metal powder. The laser beam is focussed on specific locations in the powder layer and melts the powder instantly through high temperatures. The path of the laser light is determined by the printer’s control system based on the design file.
  • l Layer build: After completing a scan, the build platform drops a fixed layer thickness (typically tens to hundreds of microns). A new layer of metal powder is then applied over the already molten area. This repeats the scanning and layer building steps layer by layer until the entire part build is complete.
  • COOLING AND SOLIDIFICATION: After completing the build, the part needs to be cooled to allow the molten metal powder to re-solidify into solid metal. Cooling can be achieved by natural or assisted cooling methods to ensure stability and strength of the part.
  • Post-processing: After completion of build and cooling, the part may require a post-processing step. This may include removal of support structures (temporary structures used to support the overhanging part), heat treatment (e.g., annealing or solution treatment) to improve material properties, and surface treatment (e.g., polishing, painting, or plating).

With these steps, selective laser fusion 3D printers can build metal parts with complex geometries layer by layer. Accurate control of the laser and precise layer-by-layer build-up allows the printer to create metal parts with high precision, good material properties and complex internal structures.

Selective Laser Melting VS Selective Laser Sintering

Selective Laser Melting (SLM) and Selective Laser Sintering (SLS) are two common metal 3D printing technologies that have some differences in their working principles and applications.

Working Principle:

SLM: SLM uses a high-energy laser beam to melt metal powders directly into a liquid state, which is then solidified by rapid solidification to form a solid metal part. The laser irradiation energy is sufficient to completely melt the metal powder and bond it to the previous layer.

SLS: SLS uses a high-energy laser beam to heat thermoplastic or sinterable powders (including plastic, ceramic, or metal powders) to near the melting point, but not to complete melting. The powder particles are bonded together by heat to form a solid part.

Material Selection:

SLM: SLM is mainly used for metallic materials such as stainless steel, titanium alloys, aluminium alloys and nickel-based alloys. It is suitable for metallic materials with high melting point and high reactivity.

·SLS: SLS can be used on a wide range of materials, including plastics, ceramics and metals. It is suitable for thermoplastic or sinterable powders, enabling a wider choice of materials.

application areas:

SLM: Due to its ability to create metal parts with high strength, precision and complex shapes, SLM is widely used in aerospace, medical, automotive, energy and manufacturing. It has advantages in the manufacture of complex parts, moulds, prototypes and personalised products.

·SLS: SLS technology is suitable for the manufacture of plastics, ceramics and composites. It has a wide range of applications in rapid prototyping, small batch production, manufacturing of functional parts and preparation of complex structures.

Overall, SLM and SLS are two different 3D printing technologies that differ in material selection and application areas.SLM is suitable for precision manufacturing of metallic materials, while SLS is suitable for manufacturing of thermoplastic or sinterable materials. Depending on the specific application requirements and material selection, choosing the right technology can lead to the desired part manufacturing.

Advantages of Selective Laser Melting 3D Printing?

Selective Laser Melting (SLM) 3D printing offers several advantages:

  1. Complex Geometries: SLM allows for the manufacture of parts with highly complex geometries, including internal cavities, curves, and thin-walled structures. Since it is a layer-by-layer build process, it is possible to achieve almost any shape without the limitations of traditional manufacturing methods.
  2. High accuracy and precision: SLM allows for very high accuracy and dimensional control, typically in the tens of microns range. This makes SLM suitable for manufacturing applications with stringent dimensional requirements and high-precision parts, such as aerospace and medical fields.
  3. Material Versatility: SLM can use a wide range of metal materials such as stainless steel, titanium alloys, aluminium alloys, nickel-based alloys, and more. This material versatility makes SLM ideal for parts that can be manufactured with excellent mechanical properties and special material characteristics.
  4. High Strength and Excellent Properties: Because SLM uses metallic materials and builds parts by completely melting and solidifying them, the resulting parts typically have high strength and excellent mechanical properties. This makes SLM suitable for applications that need to withstand high loads and harsh environments.
  5. Rapid manufacturing and customisation: SLM offers faster production speeds compared to traditional manufacturing methods. It allows complex parts to be manufactured in a short period of time, resulting in faster product development and production cycles. In addition, SLM allows customisation to meet specific customer requirements.
  6. Reducing waste and costs: SLM is an additive manufacturing technology that allows parts to be manufactured on demand, reducing material waste and inventory costs. It can also combine multiple parts into a single complex assembly, reducing the number of connections between parts and assembly processes.

In summary, selective laser fusion 3D printing technology offers the advantages of manufacturing complex geometries, high accuracy, multiple material options, excellent performance, rapid manufacturing and customisation. This makes it an attractive manufacturing method in many fields, driving innovation and productivity.

What are the application areas of Selective Laser Melting Additive Manufacturing?

Selective Laser Melting (SLM) Additive Manufacturing technology has a wide range of applications in many fields. The following are some typical application areas:

  1. Aerospace: SLM can be used to manufacture complex components in aerospace, such as combustion chambers, fuel nozzles, turbine blades and structural supports. It enables lightweight design and optimised internal structure, improving part performance and fuel efficiency.
  2. Medical sector: SLM can be used to manufacture medical devices, implants and artificial joints, among others. It allows personalised design and customised manufacturing to meet specific patient needs. In addition, SLM can manufacture medical parts with complex structures and biocompatibility.
  3. Automotive industry: SLM can be used in several aspects of automotive manufacturing, including engine components, braking systems, driveline systems and chassis structures. Through the use of SLM, lightweight designs, optimised internal structures and performance improvements can be achieved, resulting in improved fuel efficiency and vehicle performance.
  4. Energy industry: SLM can be used to manufacture gas turbine generator components, fuel cell parts and solar cell components, among others. It enables complex infusion channels, optimised heat dissipation structures and high-efficiency energy conversion devices.
  5. Manufacturing: SLM can be used to manufacture tools and moulds such as injection moulds, die-casting moulds and extrusion dies. It enables complex internal channels and cooling structures to improve mould performance and manufacturing efficiency.
  6. Art and design: SLM can be used to manufacture artwork, jewellery and personalised decorations, among others. It allows for free-form designs and complex structural representations, providing artists and designers with more creative possibilities.

In addition to the above areas, SLM has applications in shipbuilding, electronics, defence and aerospace components. As the technology develops and material choices continue to expand, SLM is expected to continue to play an important role in many more fields.

What materials are commonly used for Selective Laser Melting 3D printing?

Selective Laser Melting (SLM) 3D printing technology can be manufactured using a wide range of materials. The following are some of the commonly used materials:

  1. Stainless Steel: Stainless steel is one of the most common SLM materials. It has good mechanical properties, corrosion resistance and high temperature resistance. Commonly used stainless steel materials include 316L, 17-4 PH, 15-5 PH, and so on.
  2. Titanium Alloy: Titanium alloys are widely used in aerospace, medical and automotive applications. They have high strength, low density and good biocompatibility. Common titanium alloy materials include Ti6Al4V (also known as Ti-64) and Ti6Al4V ELI.
  3. Aluminum Alloy (Aluminum Alloy): Aluminum alloys are lightweight and have good thermal conductivity, making them suitable for use in areas such as aerospace, automotive and electronics. Commonly used aluminium alloy materials include AlSi10Mg and AlSi7Mg.
  4. Nickel-Based Alloy: Nickel-based alloys have excellent high-temperature, corrosion and abrasion resistance and are suitable for applications in high-temperature environments such as the aerospace and energy industries. Common nickel-based alloys include Inconel 718, Inconel 625 and Hastelloy X. 5.
  5. Copper Alloys (Copper Alloy): Copper alloys have good electrical and thermal conductivity and are suitable for use in the electronics, thermal conductivity and electrical industries. Common copper alloy materials include CuCr1Zr and CuNi2SiCr.

In addition to the above materials, there are some other commonly used SLM materials, such as tungsten alloy, cobalt-chromium alloy, and martensitic stainless steel. With the further development of SLM technology, new materials are emerging, providing options for a wider range of applications. It is important to select the right material to meet performance requirements and manufacturing goals based on specific application needs.

Selective Laser Melting 3D Printer Quote

Prices for Selective Laser Melting (SLM) 3D printers vary by supplier, model and configuration. These printers are typically used in a wide range of industrial and professional applications and are therefore more expensive. Here are some reference price ranges:

  1. Entry-level printers: entry-level SLM 3D printers typically cost between $10,000 and $50,000. These printers are suitable for small businesses or startups with a smaller modelling area and lower throughput.
  2. Mid-range printers: Mid-range SLM 3D printers typically cost between $50,000 and $150,000. These printers have a larger modelling area, higher throughput and more feature options for medium scale production needs.
  3. High-end printers: High-end SLM 3D printers typically cost more than $150,000 and can reach millions of dollars. These printers have the largest modelling area, highest throughput and most advanced features for mass production and professional applications.

It is important to note that the above prices are for reference only, and actual prices may vary depending on factors such as supplier, geographic location, and additional options. Also, in addition to the cost of purchasing the printer itself, other costs such as material costs, maintenance costs and training should be considered.

How to buy the right SLM 3d printer?

When it comes to Selective Laser Melting (SLM) 3D printers, here is some more information to help you make your decision:

  • Modelling area size: different SLM printers have different modelling area sizes, which determines the size of the parts you can print. If you need to print large parts or mass production, it is recommended to choose a printer with a larger modelling area.
  • Resolution and Accuracy: Resolution and accuracy affect the surface quality and detail of the printed part. Higher resolution and accuracy usually means a smoother and finer surface, but may increase print time.
  • Material compatibility: Different SLM printers are suitable for different types of metal materials, such as stainless steel, titanium, aluminium alloys, and so on. Make sure the printer supports the material you need and has the proper parameter settings and controls.
  • Control software and functionality: SLM printers usually come with dedicated control software for slicing, parameter setting and monitoring of the printing process. Understand the functionality and ease of use of the software to ensure it meets your needs.
  • Reliability and Maintenance: Understand the reliability and maintenance needs of your printer. Some key factors include machine stability, failure rates, ease of repair and maintenance, and the level of technical support and service from your supplier.
  • Cost and return on investment: SLM printers are typically more expensive, but it’s also important to consider the return on investment. Evaluate the printer’s performance, production capacity and material costs against your expected output and market demand to determine if it’s worth the investment.
  • User feedback and reviews: Check out user feedback and reviews of specific printers to understand their experience and performance. This can be accessed through online discussion forums, user reviews and professional reviews.

When choosing an SLM 3D printer, it is best to communicate with multiple vendors for detailed product information, technical support and services. Also consider visiting trade shows and exhibitions to observe and interact with suppliers in person. This will help you make an informed decision and choose the right printer for your needs and budget.

AFS focus on 3D printing equipment and rapid manufacturing services, the company has nearly 30 years of 3D printing industry, launched a series of 3D printers, including sand 3D printer (binder jetting process, SLS process), metal 3D printer, wax mould 3D printer, etc., at present, a large number of applications with major enterprises, colleges and universities and scientific research institutes, and at the same time, has been working with the global enterprises. The price of 3D printing equipment varies by country, region and configuration. If you need to buy or become an agent, you can click here to contact us.

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