June 2019 – Zirconium Metal

How is Zirconia Ceramic Cell Phone Panel Produced?

With the advent of the era of 5G signals, intelligent wearable devices are bound to shift from metal to glass and ceramics. Especially, in the mobile phone panel industry, more and more mobile phone manufacturers began to use zirconia ceramic material. So what is the manufacturing process of zirconia ceramic cell phone panel?

Ceramic powder

Microcrystalline zirconium is generally used as the raw material for the shell of 3C products. Zirconia powder is the most widely used ceramic material for the shell of 3C products due to its good appearance treatment effect and the advantages of phase change toughening.

Ceramic Machining

Ceramic shell molding processes such as mobile phones and smart wear mainly include injection molding, dry pressing molding, and tape casting. Injection molding is similar to plastic injection molding, which is mainly used to produce small and sophisticated ceramic parts with complex shapes. In general, the larger the size, the less advantageous the injection molding; dry pressing mainly produces flat products with high production efficiency; tape casting is an important forming method for thin ceramic materials. The above three molding methods can be used to produce mobile phone panels.

1. Injection molding

Ceramic Injection Molding (CIM) is a new process for ceramic parts manufacturing combining polymer Injection Molding with ceramic manufacturing.

2. Dry Pressing

Dry compression molding is a method to make the powder into a certain shape of the blank body by applying external pressure through the plunger of the press. Due to the moisture content of powder under 7%, the subsequent sintering time is reduced, so the forming efficiency is high and the cost is low, but the density is not uniform.

3. Tape casting

Tape casting is an important forming method for thin ceramic materials with high productivity and automation, but the shrinkage rate of firing is as high as 20-21%. It can be used to prepare high-quality ceramic films with a thickness of 10-1000 microns. Tape casting is used in the ceramic panel of MI 5 mobile phones and the ceramic fingerprint cover of various mobile phones.

4. Debinding and sintering

Debinding is the removal of organic matter from the body of an injection-molded billet by heating or other physicochemical means.

Under the action of high temperature, with the extension of time, the green body finally becomes a hard polycrystalline sintered body with a certain microstructure, which is called sintering. Sintering is a process to reduce the pores in the forming body, enhance the combination of particles and improve mechanical strength.

5. Postprocessing

The panel of 3C products, such as mobile phones and smart wearers, has very high requirements on the surface effect of engineering ceramics, such as smooth and clean surface, precise geometric size, fingerprint protection, and so on. This requires a complex post-processing process, including CNC machining, grinding, polishing, laser /PVD, AF processing, etc.

The above is all about the production process of the zirconia ceramic cell phone panel, I hope it can provide a reference for you. Stanford Advanced Materials supplies high-quality zirconia products to meet our customers’ R&D and production needs. Please visit http://www.samaterials.com for more information.

What Do You Know About Zirconium And Zirconium Alloys?

Compared with traditional iron, copper, nickel, and other metal elements, zirconium has a lower density and smaller thermal expansion coefficient. In addition, zirconium has a low thermal neutron absorption cross-section (only 0.18×10-28 m2) and good corrosion resistance, which makes zirconium and zirconium alloys have a wide range of applications in the nuclear industry, aerospace and other special fields.

Zirconium and its alloys have been widely used as cladding materials in nuclear reactors. Zirconium and its alloys reflect neutrons back into the reactor more efficiently than stainless steel, greatly saving uranium fuel; Zirconium alloy has good corrosion resistance at high temperature and high-pressure steam of 300 ~ 400 ℃, which also makes the reactor have a long service life. Therefore, zirconium is regarded as the first metal in the atomic age.

Development status of zirconium and its alloys

Zirconium, which is found in the earth’s crust at about 220 g /t, ranks 20th, ahead of other common metals such as copper, nickel, lead, and cobalt. Initially, zirconium alloys were mainly used as cladding materials in the nuclear industry. In recent decades, zirconium alloys have been widely used in the chemical industry, medical industry, and some special fields.

Zirconium alloy for nuclear use

Zirconium alloys have been widely used in the nuclear industry because of their very low thermal neutron absorption cross-section and good resistance to high temperature and pressure corrosion. France, the United States, Germany, and Russia have developed a series of zirconium alloys for nuclear use. At present, Zr-2, Zr-4, Zr2.5nb and ZIRLO, E635, M5, and NDA zirconium alloys have been successfully applied in the nuclear industry. These newly developed zirconium alloys have lower radiation creep properties and better resistance to iodine stress corrosion. In addition, they are able to meet the requirements of high burnup of the fuel assemblies, increasing the service life of the assemblies to 30 years.

Corrosion-resistant zirconium alloy

Zirconium has excellent corrosion resistance against most organic acids, inorganic acids, strong alkalis, and some molten salts. Therefore, zirconium can be used to improve the service life of some key components in corrosive environments. Another way to improve the corrosion resistance of alloy parts is surface pretreatment. In industry, zirconium is placed in high-temperature air to obtain a dense oxide film, so as to improve the corrosion resistance and erosion resistance of zirconium and its alloys. The results show that the corrosion rate of zirconium treated by surface oxidation in sulfuric acid medium is only 5% of that of pure zirconium, but the erosion resistance is increased by twice.

At present, zirconium is widely used as corrosion-resistant material in the chemical industry, and it has been widely used in the heat exchanger, dike washing tower, reactor, pump, valve, and corrosion medium pipeline. For example, zirconium alloys have been used to produce concentrated and hydrolyzed tubes in hydrogen peroxide production lines, while zirconium pressure reducing valves, agitators and flow meters are used in fertilizer production, sewage treatment, and dye industries.

Biomedical materials are a new high-tech material in recent years, and biomedical alloys must have good compatibility and corrosion resistance with the environment of biological fluids. Zirconium is valued by researchers for its good biocompatibility, elastic modulus similar to bone and corrosion resistance. Ti6Al4V, a titanium alloy implanted earlier in hard tissues of the human body, has an elastic modulus of nearly 110 GPa, which is much higher than the elastic modulus of 15 ~ 30 GPa of natural bones of the human body.

High-strength zirconium alloy

In the fields of space exploration, deep-sea exploration, and high-speed railway, there are often some special operating environments, such as the alternating temperature environment of -200 ~ 200 ℃, continuous space irradiation, and relative motion of structural parts, etc. Under these special circumstances, long-serving structural components are often faced with fatigue damage, dimensional instability, atomic oxygen erosion, and friction wear. At present, the structural parts used in these special fields are mainly made of 20Cr, GCr15, and other alloy steel materials, which often have problems such as poor radiation resistance, easy damage of moving parts, high density, and high cost.

Compared with traditional alloy steels, zirconium and its alloys have several important potentials:

The thermal expansion coefficient of zirconium is small and the size structure is stable, so it has the potential to produce precise structural components;
It has the potential of resisting space radiation damage;
It has the potential to resist atomic oxygen erosion;

Therefore, zirconium and its alloys are expected to adapt to unconventional environmental conditions in special fields and have the potential to be used as structural components in special environments.

Please visit http://www.samaterials.com for more information.

Zirconia Ceramics: A Hotspot in the Field of Micro-machinery

Zirconia ceramic materials are gradually being widely used in the field of micromachinery, because of its maintain excellent properties such as high-temperature resistance, oxidation resistance, acid and alkali corrosion resistance, hardness, etc.

The development of science and technology has made the miniaturization technology of zirconia ceramic materials become an important issue concerned by all countries, while the equipment tends to be miniaturized, and zirconia ceramics have a broad application prospect in the fields of automobile, medical treatment, aviation, aerospace, military, and environmental detection.

All countries in the world began to invest a lot of money, scientific research forces and too micromechanical system research. Organizations such as the National Natural Science Foundation of the United States and the Department of Defense attach great importance to MEMS（Micro-electromechanical Systems）technology and invest a lot of money in related research; The European Union has set up a multi-functional Microsystems research cooperation agency to strengthen interaction among countries; Japan has formulated the nano-manufacturing plan, the AI（artificial intelligence）technology plan, the microrobot plan, and established the micro machinery center and the micro machinery society; At present, there are more than 60 units engaged in MEMS research in China, and some scientific achievements have been made in the field of sensors and micro-actuators.

Zirconia ceramics are used in micro pressure sensors to detect engine inlet pipe pressure, micro accelerometers for vehicle safety airbag systems, and micro angular velocimeters for wheel sideslip and roll control. Microdevices such as micro pumps, microvalves, micro tweezers, and micro flowmeters applied in zirconia ceramics, and the micro-inertial measurement device, micro-whole analysis system, RF sensor, etc. are used in the military field. Moreover, zirconia ceramic materials can be used as a micro burner, a microreactor, and a pressure sensor at high temperatures and they can also be used as a composite, bone tissue scaffold, and in other biomedical fields because of their good biological solubility.

Please visit http://www.samaterials.com for more information.

Alumina VS Zirconia

Alumina (Al2O3) is a very common technical ceramic material. Zirconia (ZrO2), including yttrium stabilized zirconia (YSZ), is also widely used in machinery industries. Since both of them are oxide materials and could be sintered without vacuum, they share a lot in manufacturing equipment and have a similar appearance. However, there are still quite a lot of differences between these two materials.

Price: alumina VS zirconia

The most significant difference between these two materials is the price. Cost for zirconia is more than doubled for even the best alumina material. One of the reasons is the cost of the raw material. Compared with Zirconium, Aluminum is far more abundant in the crust and it’s much cheaper. On the other hand, Yttrium oxide, widely used as a stabilizer for Zirconia, is a rare earth element with limited sources.

However, it is the cost of shaping zirconia that contributes the major part. The density of zirconia is much higher than alumina and the wear resistance of zirconia is far better than alumina. To ground down the same thicknesses for zirconia takes almost 10x more time than alumina and consumes more diamond tools. Also, since the thermal shock resistance for zirconia is poor and requires a higher sintering temperature, the sintering process also costs more than alumina.

Applications: alumina VS zirconia

As the wear resistance for zirconia is much better, it is frequently used as mortar and pestles, grinding jars and grinding media, bearing balls and ceramic parts in valves and pumps. Zirconia parts will last longer in machines and have less contamination than grinding jars. Zirconia is generally better in mechanical applications but alumina is a better bulletproof material due to the lower density.

Although zirconia could withstand higher temperatures, application in industrial furnaces is rare. The advantage in working temperature is not quite significant, while the cost for zirconia is much higher.

High-density ZrO2 also provides better corrosion resistance. Zirconia could survive longer in a highly corrosive environment and is considered better material in chemistry laboratories.

Generally, zirconia performs better if the density and heat shock resistance is not considered. Stanford Advanced Materials (SAM) is a trusted supplier of customized zirconia products, such as zirconia rods, zirconia crucibles, zirconia tubes, etc. Please visit http://www.samaterials.com for more information.