Request pdf mechanical and thermal properties of 99% and 92% alumina at cryogenic temperatures in the present paper, mechanical properties with respect. Alumina aluminium oxide al2o3 a refractory ceramic oxide. It has the second lowest strength compared to the other variants of alumina. Alumina ceramics are commonly subdivided according to their alumina content ranging from 80% to more than 99 %.
Our fabricated alumina is used in a wide range of applications not limited to. Aluminum oxide al 2 o 3, commonly known as alumina, is extensively used as an engineering ceramic due to its high performance at a costeffective price. Alumina engineered ceramic parts can be formed by single axis pressing. Typical values of thermal expansion coefficient, specific heat, enthalpy. This material has superb material characteristics such as high electrical insulation, high mechanical strength, high wear and chemical resistance. Duco ceramics companys crushable alumina ceramics have excellent wear resistance, high temperature properties and excellent mechanical strength. The result is a performance combination that is tougher than alumina alone, but with improved hardness, strength and thermal properties compared to these other materials, especially at elevated temperature. For more information and advice please discuss your application with our sales staff. High purity commercial alumina 99,9% a1203 has a hexagonal or rhombic crystal structure, with a grain. Applied ceramics manufactures its aci995 alumina into different shapes such as disks, rings rectangles and custom designs requiring high specifications and tolerances. The aluminum oxide content of the finished ceramic determines many of its final properties, and the properties of a. It is possible to machine alumina using diamond grinding techniques. Our ceramic cylinders are made with an alumina content 92% with very high thermal resitance.
The change in temperature where a sharp decrease in flexural strength is observed is listed as dtc. A high purity material used for the highest integrity applications where one, or a combination, of its exceptional mechanical, electrical, thermal or corrosion resistant properties is essential. Our alumina products also exhibit excellent mechanical strength, and can operate at safe operating temperatures up to 1650 c. Alumina oxide ceramics al2o3 is the most widely used fine ceramics material.
Broadband dielectric characterization of aluminum oxide. Our fabricated alumina is used in a wide range of applications not limited to aerospace, automotive, medical and military. All aluminas are very hard and wear resistant, with high compressive strength even against extreme temperatures and corrosive environments. Property values below are taken from literature and manufacturer sources. Alumina is produced by firing a tightly packed powder form of al2o3 which includes some binder material. It is recommended that materials and components are tested for their suitability for a specific application. The raw materials from which this high performance technical grade ceramic is made are readily available and reasonably priced, resulting in good value for the cost in fabricated alumina shapes. Advanced ceramic material properties for the electronics. Alumina is the most wellknown and most commonly used fine ceramic material. Alumina is here graded into two main groups, the first of high alumina grades with at least 99 % al2o3 table 1 and the second of alumina grades between 80% and 99 % al2o3 table 2. Alumina ceramics are commonly subdivided according to their alumina content ranging from 80% to more than 99%. It has been used for decades in electrical components for its high electrical insulation, and is widely used in mechanical parts for its high strength, and corrosion. Aluminum oxide is an amphoteric oxide of aluminum with the chemical formula al2 o 3. All properties are room temperature values except as noted.
Request pdf mechanical and thermal properties of 99% and 92% alumina at cryogenic temperatures in the present paper, mechanical properties with respect to bending strength and fracture. The indices in the chart are calculated by dividing the material volume loss by the volume loss of an ad85 alumina control. Our product are suitable for a wide range of application fields. This is a highly versatile alumina ceramic with great mechanical, electrical, thermal, and chemical properties, featuring. The graph bars on the material properties cards below compare type iii alumina to other oxidebased engineering ceramics top and the entire database bottom. It is used as an adsorbent, desiccating agent, and catalyst, and in the manufacture of dental cements and refractories. Al998 is a unique material as free silica in the grain boundaries have been eliminated and it has low sodium purity levels which enable fine finishes and polishes to be achieved. Because hightemperature processes demand reliable components, our alumina tubes are most apt. Aluminas are used in both general use and specialized applications. Commercially available grades range from 90% up to 99. This material has less flexural strength, thermal conductivity, dielectric strength and dielectric constant than 99. Alumina is generally available in two concentrations. Alumina oxide al2o3 is a readily available material with reasonable processing cost, possessing excellent mechanical, electrical, and wear properties.
High purity alumina is also capable of very fine surface finishes suitable for valves, pump components and seals. Alumina ceramics have excellent electrical, wear resistant, and high temperature properties. Alumina or aluminium oxide, al 2 o 3 is a major engineering material. Mechanical and physical properties of engineering alumina. See the chemical composition and physical properties of alumina powder 99. Zirconiatoughened alumina is a modified, stronger grade of alumina. Typical applications include, but are not limited to, high temperature thermocouple insulators, resistance temperature detector rtds, differential thermal analysis dtas. Expecially the alumina99 balls present a content 99%. Alumina can be produced in a range of purities with additives designed to enhance properties. An oxide of aluminum, occurring in nature as various minerals such as bauxite, corundum, etc. This ceramic is the workhorse of the microwave integrated circuit mic business. Alumina is here graded into two main groups, the first of highalumina grades with at least 99% al2o3 table 1 and the second of alumina grades between 80% and 99% al2o3 table 2. Excellent thermal properties denstone 99 spheres can withstand temperatures up to 1650c and.
Keywords aluminium oxide, ceramics, mechanical properties, physical. Annual world production of alumina is approximately 45 million tons and over 90. Alumina aluminum oxide, al2o3 fine ceramics advanced. Properties shown are typical values, they are not absolute material properties, and should be used for guidance only. The data presented is typical of commercially available material and is offered for comparative. Ceramic property values vary somewhat with method of manufacture, size, and shape of part. It has been used for decades in electrical components for its high electrical insulation, and is widely used in mechanical parts for its high strength, and corrosion and wearresistance. A wide variety of ceramic processing methods can be applied. Rubbing tests are run using a dry 240 grit fused alumina abrasive. Aluminium oxide al2o3 or alumina is one of the most versatile of. Typically, alumina is available in grades from 88% to 99. Mechanical and thermal properties of 99% and 92% alumina. Alumina a03 was known, however, in the eighteenth century, and the first unsuccessful attempts to isolate the metal were made by sir humphry davy in 1807, when the isolation of the alkali metals had made a powerful reducing agent available.
With over 20 years of experience in alumina ceramic manufacturing, the ultraprecision parts made by applied ceramics aci 99. Additional options include blends of zirconia with alumina and silicon nitride with alumina. Wear reistance impingement tests are run using a dry fused alumina abrasive. Properties of alumina provided include physical, mechanical, thermal and electrical properties. Effect of mgoal2o3sio2 glassceramic as sintering aid on. In this paper, the correlation between mechanical properties and ballistic performance of nonstoichiometric cordieritebased glassceramicalumina composites arrays with 99. Duco ceramics company a leader in the technical ceramics industry since 1949 call. It offers a combination of good mechanical properties and electrical properties leading to a wide range of applications. Alumina 99,7% the performance of the material in high temperature situations is largely related to the content of alumina. It has the same sintered crystal body as sapphire and ruby. The precursor alumina had average particle sizes of 0. A full bar means this is the highest value in the relevant set.
Variations are possible among various commercial grades. Close control of values of most properties can maintained if specified. The first sample is 96% alumina and 4% glass, and the second sample is composed of 99. Characteristics of kyocera fine ceramics1 04 for product details, please contactwebmaster. Higher purity alumina demonstrates enhanced wear and corrosion resistance creating a continuous scale of various alumina grades, compositions, and performance. Mechanical and thermal properties of 99% and 92% alumina at. The lower in the index, the better the wear resistance. High purity commercial alumina 99,9% a1 2 0 3 has a hexagonal or rhombic crystal structure, with a grain size between 15 microns, density from 3.
The chart is intended to illustrate typical properties. With over 20 years of experience in alumina ceramic manufacturing, the ultraprecision parts made by applied ceramics aci99. Alumina is one of the most cost effective and widely used material in the family of engineering ceramics. Aluminum oxide is an electrical insulator but has a relatively high thermal conductivity 30 wm. Based on initial evaluation by two refractory manufacturers in brick or castable applications, the new aggregate offered adequate strength with thermal conductivity reductions up to 34%, depending on the. Laboratory and industrial furnace applications up to 1400c uses alumina tubes 99.