The current development status of 3D printing materials

The rapid development of 3D printing technology has made it the focus of rapid prototyping technology research at home and abroad in recent years.At present, the United States, Europe, and Japan are all standing at the strategic height of manufacturing competition in the 21st century, and have invested a lot of research on rapid prototyping technology, which has enabled the rapid development of 3D printing technology.In the field of national defense, developed countries in Europe and the United States attach great importance to the application of 3D printing technology, and have invested heavily in the development of additive manufacturing of metal parts, especially vigorously promoting the application of additive manufacturing technology in the manufacture of high-value materials such as titanium alloys.Materials are the material basis of 3D printing and are also the bottleneck restricting the development of 3D printing. Here is a brief introduction to the current development status of 3D printing materials.

3D printing materials are an important material basis for the development of 3D printing technology. To a certain extent, the development of materials determines whether 3D printing can be more widely used.At present, 3D printing materials mainly include engineering plastics, photosensitive resins, rubber materials, metal materials and ceramic materials. In addition, food materials such as colored plaster materials, artificial bone meal, cell biological materials, and sugar are also available in the field of 3D printing.了 Application. These raw materials used in 3D printing are specially developed for 3D printing equipment and processes. They are different from ordinary plastics, gypsum, resins, etc., and their forms are generally powder, filament, layered, liquid, etc.Generally, depending on the type of printing equipment and operating conditions, the particle size of the powdered 3D printing materials used varies from 1 to 100 μm. In order to maintain good fluidity of the powder, the powder is generally required to have a high degree of sphericity.

1. Engineering Plastics

Engineering plastics refer to industrial plastics used as industrial parts or housing materials. They are plastics with excellent strength, impact resistance, heat resistance, hardness and aging resistance.Engineering plastics are currently the most widely used type of 3D printing materials. Common ones are acrylonitrile butadiene styrene (ABS), polycarbonate (PC), nylon, etc. ABS material is a thermoplastic engineering plastic commonly used in fused deposition modeling (FDM) rapid prototyping process. It has the advantages of high strength, good toughness, and impact resistance. The normal deformation temperature exceeds 90 ℃, and it can be mechanically processed (drilling, tapping, etc.). Thread), painting and electroplating.

There are many colors of ABS materials, such as ivory white, white, black, dark gray, red, blue, rose red, etc., and are widely used in the fields of automobiles, home appliances, and consumer electronics.

PC material is a true thermoplastic material, with all the characteristics of engineering plastics: high strength, high temperature resistance, impact resistance, bending resistance, and can be used as final parts.Samples made of PC materials can be directly assembled and used in the transportation and home appliance industries. The color of PC material is relatively single, only white, but its strength is about 60% higher than that of ABS material. It has super engineering material properties and is widely used in consumer electronics, home appliances, automobile manufacturing, aerospace, medical equipment and other fields.

Nylon glass fiber is a kind of white powder. Compared with ordinary plastics, its tensile strength and bending strength are enhanced, heat distortion temperature and material modulus are increased, and the shrinkage rate of the material is reduced, but the surface becomes rough. , The impact strength is reduced.The material has a heat distortion temperature of 110°C and is mainly used in the fields of automobiles, home appliances, and consumer electronics.

PC-ABS material is one of the most widely used thermoplastic engineering plastics. PC-ABS has the toughness of ABS and the high strength and heat resistance of PC materials, and is mostly used in automobiles, home appliances and communications industries.The strength of the prototype made with this material and the FORTUS equipment is about 60% higher than that of the traditional FDM system. Therefore, using PC-ABS can print out thermoplastic parts including conceptual models, functional prototypes, manufacturing tools, and final parts. .

The polycarbonate-iso (PC-ISO) material is a white thermoplastic material that has passed the medical and health certification. It has high strength and is widely used in the pharmaceutical and medical device industries for surgical simulation, skull restoration, dentistry and other professional fields.At the same time, because it has all the performance of PC, it can also be used in the food and pharmaceutical packaging industry. The samples made can be used as conceptual models, functional prototypes, manufacturing tools and final parts.

The class material is an amber material with a heat distortion temperature of 189°C. It is the material with the highest strength, heat resistance, and corrosion resistance of all thermoplastic materials. It is usually used as a final component and is widely used in aviation. Aerospace, transportation and medical industries. PSU materials can bring a direct digital manufacturing experience, with very stable performance, and can achieve amazing results through the use of RORTUS equipment.

2. Photosensitive resin

The photosensitive resin is ultraviolet rays (UV) resin, which is composed of polymer monomers and prepolymers, and a light (ultraviolet light) initiator (or called a photosensitizer) is added to it.Under the irradiation of a certain wavelength of ultraviolet light (2500～300nm), it can immediately cause the polymerization reaction to complete the curing.The photosensitive resin is generally liquid and can be used to make high-strength, high-temperature resistant, and waterproof materials.At present, 3D printing technology of photosensitive materials is mainly researched by the United States 3Dsystem company and Israel object company.Common photosensitive resins are somos NEXT material, resin somos11122 material, somos19120 material and epoxy resin.

The somos NEXT material is a white material, a new PC-like material, with very good toughness, and can basically reach the performance of nylon material made by selective laser sintering (SLS), and the accuracy and surface quality are better. Parts made of somos NEXT material have the best rigidity and toughness so far, while maintaining the advantages of exquisite workmanship, precise size and beautiful appearance of light-cured three-dimensional modeling materials. They are mainly used in automobiles, home appliances, consumer electronics and other fields.

The somos11122 material looks more like a real transparent plastic, has excellent waterproof and dimensional stability, and can provide a variety of similar engineering plastic characteristics including ABS and PBT. These characteristics make it very suitable for use in automobiles, medical and The field of electronic products.

The somos19120 material is pink, which is a special casting material.After molding, it can directly replace the wax film prototype of precision casting, avoiding the risk of developing molds, greatly shortening the cycle, and having the characteristics of low ash retention and high precision.

Epoxy resin is a laser rapid prototyping resin that is easy to cast. It contains very low ash content (residual ash content at 800℃<0.01%), and can be used in fused silica and alumina high-temperature shell systems, and does not contain heavy metals. Antimony can be used to make extremely precise rapid casting molds.

3. Rubber materials

Rubber materials have the characteristics of multiple levels of elastic materials. The hardness, elongation at break, tear strength and tensile strength of these materials make them very suitable for applications requiring non-slip or soft surfaces. 3D printed rubber products mainly include consumer electronics, medical equipment, automotive interiors, tires, and gaskets.

4. Metal materials

In recent years, 3D printing technology has gradually been applied to the manufacture of actual products. Among them, the 3D printing technology of metal materials has developed particularly rapidly.In the field of national defense, developed countries in Europe and the United States attach great importance to the development of 3D printing technology and have invested heavily in research. 3D printing of metal parts has always been the focus of research and application. The metal powder used in 3D printing generally requires high purity, good sphericity, narrow particle size distribution, and low oxygen content.At present, the metal powder materials used in 3D printing mainly include titanium alloy, cobalt-chromium alloy, stainless steel and aluminum alloy materials, in addition to precious metal powder materials such as gold and silver used for printing jewelry.

Titanium is an important structural metal. Titanium alloys are widely used in the production of aircraft engine compressor parts, as well as various structural parts of rockets, missiles and airplanes because of their high strength, good corrosion resistance, and high heat resistance.Cobalt-chromium alloy is a high-temperature alloy with cobalt and chromium as the main components. It has excellent corrosion resistance and mechanical properties. The parts made of it have high strength and high temperature resistance.The titanium alloy and cobalt-chromium alloy parts manufactured by 3D printing technology have very high strength and precise dimensions. The smallest size that can be produced can reach 1mm, and the mechanical properties of the parts are better than the forging process.

Stainless steel is widely used because of its resistance to weak corrosive media such as air, steam, and water, and chemical corrosive media such as acids, alkalis, and salts.Stainless steel powder is a kind of cost-effective metal powder material often used in metal 3D printing. The 3D printed stainless steel model has high strength and is suitable for printing larger items.

5. Ceramic materials

Ceramic materials have excellent characteristics such as high strength, high hardness, high temperature resistance, low density, good chemical stability, and corrosion resistance. They are widely used in aerospace, automotive, biological and other industries.However, due to the hard and brittle characteristics of ceramic materials, it is particularly difficult to process and shape, especially complex ceramic parts need to be formed by molds.The high mold processing cost and long development cycle make it difficult to meet the demand for continuous product updates.