5 วัสดุโลหะยอดนิยมสำหรับเครื่องพิมพ์ 3 มิติระบบ SLM - ไทเทเนียม นิกเกิ

Metal Printing Technology with SLM 3D Printers

Metal 3D printing has garnered significant attention over the past few years, as it has the potential to drastically transform product design, production time, and costs. However, the price tag for an SLM 3D printer remains very high, comparable to other expensive industrial machinery. As a result, only large-scale industries invest in these machines. In Thailand, the number of such machines is relatively low because our country focuses on OEM manufacturing or high-volume production, where the average price point does not justify the investment. Nevertheless, over the next 10-20 years, the prices of machines and materials are expected to decline, eventually making it feasible for SMEs to invest. Business owners who stay ahead of the trend and calculate the cost-benefit ratio to find the right entry point can easily gain an edge over their competitors. For those still unsure which technology suits them best, please read this article: “3D Printer Technology Information,” or if you are interested in metal printing, start with this article: “Introduction to Metal Printing Technology.”

The working principle of an SLM (Selective Laser Melting) 3D printer uses a high-energy laser—either CO2 or Fiber, depending on the brand (a Blue Diode system developed by Japan is also available today)—to fire at metal powder, causing it to melt and fuse together. Each type of material requires different operating parameter settings. There are 5 main types of materials used for metal 3D printers, based on data from Grandviewresearch.

Titanium: A lightweight material with high strength, suitable for medical applications.
Nickel group: Often alloyed with other metals, such as Nickel-Chromium (Inconel), providing high strength and heat resistance.
Steel group: Often alloyed with other metals, such as 316L stainless steel or 17PH-4, which are widely used.
Aluminium: Lightweight with medium strength, easy to machine further using CNC or other equipment.
Other metals: Such as Cobalt Chrome, brass, gold, etc.

Alloys are relatively expensive; therefore, they are used only when necessary and when specific properties different from standard materials are required.

1. Titanium

This is a popular metal material known for high strength, including resistance to tensile and bending forces, as well as low density, resulting in a high strength-to-weight ratio. With a high melting point of 1,600 degrees Celsius, it is widely used in aerospace and space industries due to these properties.

In the medical field, it is often used to produce prosthetic bones for various parts of the body, such as legs, knees, the spine, or the skull. These implants are biocompatible and can be permanently placed within the patient's body without causing adverse reactions (they do not need to be surgically removed), making it a popular bio-material. Titanium is often alloyed with various metals to enhance its properties. For 3D printing, the popular choice is Titanium 6AI-4V, consisting of Titanium (88-90%), Aluminum (5.50-6.5%), and Vanadium (3.50-4.50%) (Source: Sculpteo), or high-grade materials like Ti Grade 2, specifically for medical use.

For titanium 3D printing, most printer brands already support this metal (the Nickel family is another popular group). When purchasing a machine, focus on the standard materials provided by the manufacturer to see if they are suitable for your specific application or if they require custom formulations, which would entail significant additional costs beyond the machine itself.

2. Nickel Group

The term "group" is used because pure nickel is rarely printed; it is usually alloyed with other metals. A popular variant is mixing it with Chromium (14-30%), Molybdenum (8-10%), and Ferrum (3-10%). This group is known as “Inconel” and is another material popular for 3D printing, especially Inconel 620, 625, 718, and 939. Most commercial machines support these, or if not, printing parameters can be adjusted for experimentation.

The main properties of Inconel are corrosion resistance and high-temperature tolerance—some grades can withstand up to 1,400 degrees Celsius without losing structural strength, a key advantage over other metals. Consequently, it is primarily used in the aerospace industry, such as for turbines, combustion engine parts, or parts in the petroleum industry that face high chemical corrosion. Some are also used to manufacture various types of chemical filters.

3. Steel Group

Manufacturers sometimes categorize this under Tool and Stainless Steel. The primary materials used are 316L stainless steel, 17P4-H, and H13. The properties of this group vary depending on the alloying elements. For example:

The Stainless Steel subgroup is alloyed with Chromium, Nickel, and Molybdenum to resist corrosion, especially from chlorine-based substances, and is strong and tough, making it suitable for chemical, food, or aerospace industries.

The Tool steel subgroup is alloyed to enhance hardness, compressive strength, and toughness, suitable for manufacturing jigs and fixtures, or inserts in injection molds where chemical corrosion is not a factor.

4. Aluminium Group

Aluminium is used for applications requiring a high strength-to-weight ratio, such as cooling fins, or for those who need to produce metal parts using 3D printing for personal use, low-volume sales, or to replace obsolete spare parts. Aluminium is a good entry-level material as it is currently the cheapest on the market. Current available grades include:

AlSi10Mg: Has mid-range properties and is popular to use.
AlSi7Mg0.6: Excels in thermal conductivity, making it suitable for cooling fins.
AlSi9Cu3: Copper is added to improve performance at high temperatures.

5. Other Metals

Copper Group

Copper is known for its salt corrosion resistance, so it is often used for housings in marine environments. It also performs well in heat exchange applications (generally, copper has better thermal conductivity than aluminium).

Summary of Metal Materials for SLM 3D Printers

This article focuses on standard materials already supported by many printers. At the actual industrial level, developing specific formulas or alloys may be necessary, which can be tested using welding wire data—which has a source similar to 3D printer metal powder—to study properties before actual production. The information in this article will be updated as technology continues to advance.