Development Status Of 3D Printing Materials
3D printing technology, also known as “rapid forming technology” or “additive manufacturing technology”, is based on digital model files, using powdered metal or plastic bonding materials to build objects by layer-by-layer stacking technology.
At present, there are two main factors that restrict the development of 3D printing technology: printing materials and equipment. Material development is more difficult than the development of equipment. 3D printing technology is not complicated and difficult to materialize. The consumables of ordinary printers are ink and paper, but the consumables of 3D printers are mainly glue and powder, and must be specially treated, and the curing reaction speed of materials is also very high. According to the chemical composition, 3D printing materials are classified into metal materials, ceramic materials, composite materials, and polymers.
At present, most 3D printing consumables are plastic, and metal has better mechanical strength and electrical conductivity, and plays a pivotal role in 3D printing. However, the 3D printing manufacturing technology of metallic materials is difficult, mainly because the melting point of metal is relatively high, and the sahod materials mainly include titanium alloy, cobalt chromium alloy, stainless steel and aluminum alloy.
Titanium alloys are particularly valued because of their low density, high strength, corrosion resistance and high melting point. Titanium alloys will have broad application prospects in 3D printing, aerospace and defense industries. Cobalt-chromium alloy is a high-temperature alloy mainly composed of cobalt and chromium. It has excellent corrosion resistance and mechanical properties, and its components are made of high strength and high temperature resistance. Stainless steel is widely used because it is resistant to weak corrosive media such as air, steam, water, and chemically aggressive media such as acids, alkalis, and salts. Stainless steel is the cheapest metal printing material and the printed model has a high strength. Magnesium-aluminum alloys have been widely used in the demand for strong manufacturing in the manufacturing industry because of their light weight and high strength.
2. Ceramic materials
Ceramic materials have high hardness, high strength, low density, high temperature resistance, corrosion resistance and other excellent properties, and have a wide range of applications in the automotive, biological and other industries. 3D printed ceramic products are impervious to water, heat (up to 600 °C), recyclable, non-toxic, and can be used as an ideal cookware and candlestick, ceramic tile, vase, art and other furniture decoration materials. However, its strength is not high, and the hard and brittle characteristics make it difficult to form and process. Especially the complex ceramic parts need to be formed by grinding tools, and the mold processing cost is high and the development cycle is long, which is difficult to meet the demand of the product.
It has been reported that researchers at the University of the West of England have developed an improved 3D printed ceramic technology that can be directly printed, fired, glazed and decorated according to CAD data, eliminating the need for previous ceramic prototypes to overfire or test enamel. Question . In 2012, Belgium built a fast-made 3D printer using ceramic materials, which made it possible to produce fine and new forms of traditional ceramic technology.
3. Composite materials
In 2014, Arevo Laboratories in Silicon Valley, USA, introduced 3D printing technology for the manufacture of high-strength carbon composite end products, which printed a composite of carbon fiber reinforced nylon matrix. The nylon matrix is a lower polymer resin than PEEK.
Compared to conventional methods, 3D printing more precisely controls the orientation of carbon fibers, optimizing specific mechanical, electrical and thermal properties, rather than shaping them like conventional extrusion or injection molding methods. And since 3D printed composite parts can only be fabricated once, each layer can achieve any desired fiber orientation. The reinforcing phase of the composite material can be used not only as carbon fiber but also as glass fiber. The technology is targeted at parts for aerospace, defense and medical applications and is expected to develop lighter, stronger and longer-lasting components.
Two types of plastics which are widely used in polymers are ABS (Acrylonitrile Butadiene Styrene) and PLA (Poly Lactic Acid). ABS has high strength, good flexibility, machinability and high temperature resistance. It is the most commonly used thermoplastic for 3D printing. ABS material has many kinds of colors, PC material is single color, only white, but its intensity is about 60% higher than ABS material. PC-ABS material is an engineering plastic with excellent comprehensive performance, which has the toughness of ABS and the high strength and heat resistance of PC.
PLA is an environmentally friendly plastic that biodegrades into active compost. PLA’s ability to resist temperature changes is weak, and it deforms when the temperature exceeds 50 °C, which restricts its development in the field of 3D printing. Polysulfone (PSU) materials are among the strongest, most corrosion-resistant and heat-resistant materials of all thermoplastics and are commonly used in the final parts and are used in the transportation, aerospace and medical industries. In addition, other new polymer materials such as nylon materials, elastic plastics, etc. have also been introduced into the field of 3D printing.
However, the existing 3D printing materials, from the price point of view, a few hundred pieces of cheap 1kg, expensive about 1 million yuan, printing costs are expensive. With the development of new materials technology, more high-performance and low-cost printing materials will appear in the future, and the development of 3D technology will continue to mature, and the cost of printed products will continue to decrease. The application of 3D printing in the medical industry, bone printing, scientific research, cultural relics protection, architectural design, manufacturing, etc. will be better developed. 3D printing technology is gradually entering people’s lives, and 3D printers will become more and more civilian.