Abstract: The embodiments of the invention are directed to a synthetic ceramic comprising pyroxene-containing crystalline phase, a clast, and a glass phase, wherein at least a portion of the synthetic ceramic is plastically deformable in a certain temperature range. Other embodiments of the invention relate to a method of making a synthetic ceramic, comprising heating a green ceramic material to 900-1400° C., to a temperature sufficient to initiate partial melting of at least a portion of the green ceramic material, transferring the heated green ceramic material to a press, pressing the heated green ceramic material in a die at 1,000 to 10,000 psi, and transferring the heated, pressed green ceramic material to a furnace for cooling to form the synthetic ceramic.

Abstract: Exemplary embodiments of the present invention provide methods for forming spark plug insulators, particularly asymmetrical spark plug insulators, without required machining after an initial heating or firing of the spark plug insulator. In one exemplary embodiment, a method of forming an asymmetrical spark plug insulator is. The method includes: forming a first mixture comprising a binder formed of water and agar; forming a second mixture comprising a ceramic material; combining the first mixture and the second mixture to form a molding compound; injection molding the molding compound to form an asymmetrical spark plug insulator having a initial net shape and size; and sintering the asymmetrical spark plug insulator to cause hardening of the asymmetrical spark plug, the sintered asymmetrical spark plug having a final net shape and size.

Abstract: The invention relates to the field of ceramics and relates to composite molded articles, such are used, for example, for chip-removal tools. The object of the invention is to disclose composite molded articles that are free in the design of their surface and interface and can be produced in series production. The object is attained through ceramic and/or powder metallurgical composite molded articles comprising a green tape and an injection molded article. The object is further attained through a method in which a green tape is inserted into or placed onto a mold, and subsequently at least one ceramic and/or powder metallurgical injection molding mass is placed on and/or applied to and/or inserted into the mold by means of injection molding, and subsequently the one-part or multi-part mold is removed and/or the one-part or multi-part composite molded part parts are removed from the mold, wherein these process steps can be repeated once or several times.

Abstract: A method of molding provides two molds (102, 104) formed of semiconductor material. The molds (102, 104) have substantially planar working faces (108, 110) into which recesses (106, 112) are formed. In use the molds (102, 104) are pressed together with the working faces (108, 110) opposed so the recesses (106, 112) form mold cavities. The molds (102, 104) only contact each other in the plane of the working faces (108, 110). A thermoplastic sheet placed between the molds is heated to deform the sheet into the mold cavities.

Abstract: Embodiments of the present invention disclosed herein include a sintering aid composition that has a material useful for sintering, an amine, and optionally a carboxylic acid.

Abstract: The invention relates to a sintered material which is based on transition metal diborides and comprises a) as main phase, 90-99% by weight of a fine-grained transition metal diboride or transition metal diboride mixed crystal comprising at least two transition metal diborides or mixtures of such diboride mixed crystals or mixtures of such diboride mixed crystals with one or more transition metal diborides, where the transition metals are selected from sub-groups IV to VI of the Periodic Table, b) as second phase, 1-5% by weight of particulate boron carbide and/or silicon carbide and c) optionally as third phase, up to 5% by weight of a non-continuous, oxygen-containing grain boundary phase.

Abstract: A composite of a metal matrix with one or more incorporated secondary phases is referred to as a metal matrix composite (MMC). Secondary phase refers to all the particles or fibers which have a different composition than the metal matrix, and which are incorporated therein. As incorporation phases, elements and compounds are possible which, as a result of their material characteristics, are suited for improving individual properties of the metal matrix. Besides an improvement in individual properties of the pure metal matrix as a result of the incorporated secondary phase, certain properties of the metal are also degraded, in particular by particles having a size of 1 to 50 ?m. For example, the elongation at break decreases, the strength may decrease, or the tribology may become less favorable.

Abstract: A method of forming a porous mullite composition of acicular mullite grains having improved properties is described, where the mullite is formed at some time in the presence of a fluorine containing gas. For example, it has been discovered that improved properties may result from heating the mullite to a high temperature in an atmosphere selected from the group consisting of water vapor, oxygen, an inert gas or mixtures thereof or forming the mullite composition from precursors having an AL/Si ratio of at most 2.95.

Abstract: A composite material is obtained by mixing with water 100 parts in weight of binder, between 250 and 800 parts in weight of steel-based shot having a granulometric distribution comprised between 120 jim and 3000 jim, between 10 and 15 parts in weight of non-densified silica fume and a highly water-reducing superplasticizer. The ratio between the weight quantity of water and the weight quantity of hydraulic binder is comprised between 0.16 and 0.25. The composite material presents a very high abrasion resistance, an abrasion index measured according to the C.N.R protocol comprised between 0.15 and 1.0, the value of the D10 grain size of the shot being at least eight times greater than the value of the D90 grain size of the hydraulic binder.

Abstract: A fastener includes a fastener body with a peripheral surface that is configured to be received in a mold assembly. The body is divided into an encased portion and an exposed portion. The encased portion is configured to be surrounded by molding material. The exposed portion is configured to be void of molding material. A crush rib extends along at least a portion of the peripheral surface at an interface between the encased portion and the exposed portion.

Abstract: An exercise hurdle including a base extending substantially horizontally outwardly from adjacent a periphery of a bottom end of a substantially wedge-shaped upwardly extending tower that angles inwardly from its bottom end to define an elongate crest line. The tower is composed of a soft, resilient polymeric material to prevent injury during use of the exercise hurdle.

Abstract: The present invention relates to a method of making a sintered body comprising one or more hard constituents in a binder phase by injection molding or extrusion. According to the invention, the binder system comprises 30-70 wt % poly(ethylene-co-vinylacetate) and balance (Polyethylene)-blend-(Poly(oxy-1,2-ethanediyl), .alpha.-hydro-.omega.-hydroxy)-based wax. The solids loading of the feedstock, ?, is 0.51<?<0.53, calculated using the equation: ? = ? f - ? b ? s - ? b where ?s is the density of the material as sintered, ?b is the density of the binder system and ?f is the density of the feedstock, measured with a helium pycnometer. Debinding is performed by heating in a furnace in flowing hydrogen atmosphere.

Abstract: A gas barrier substrate includes a compound gradient layer. The compound gradient layer includes an inorganic material and a resin material. A content of the inorganic material in the resin material varies in a thickness direction. The gas barrier substrate also includes a gas barrier layer. The gas barrier layer is made of an inorganic material and is bonded to the compound gradient layer. The compound gradient layer has a high content of inorganic material in an area near a bonding surface between the compound gradient layer and the gas barrier layer. The compound gradient layer may be bonded to a resin layer and may have a low content of inorganic material in an area near a surface bonded to the resin layer.

Abstract: A plasticizing cylinder for processing plasticizable material includes a pressure jacket, at least one heating element disposed at one area of the pressure jacket, and at least one cooling element disposed at another area of the pressure jacket. Extending within a wall of the pressure jacket between the area of the heating element and the area of the cooling element is a plurality of heat pipes, with each heat pipe having at least one section constructed with a capillary structure.

Abstract: The present invention relates to a method of fabricating a micro device, comprising the steps of pressing an upper mold formed with a plurality of recesses for molding a plurality of rods and a lower mold formed with a seat recess for molding a plate supporting the plurality of rods against each other; injecting ceramic material mixed with a polymer into the mold; releasing a resultant ceramic molding mixed with the polymer from the molds; removing the polymer from the ceramic molding by burning out or melting away the polymer; sintering the ceramic molding; filling a polymer into spaces between the plurality of rods of the sintered ceramic molding so that the top surfaces of the plurality of rods are exposed to the outside; and removing the plate through a polishing process so that bottom surfaces of the plurality of rods are exposed to the outside.

Abstract: Annular brake disc preform (15), wherein 40 to 80 layers of reinforcement fibers of at least two different lengths (11, 19) ranging from 10–60 mm are distributed in a planar gradient throughout the body of the preform, with the reinforcement fibers located near the exterior planes of the disc being predominately shorter fibers (11) and with the reinforcement fibers located in the central planes of the disc being predominately longer fibers (19).

Abstract: According to a known method for producing a component by means of a powdery starting material, powder is mixed with auxiliaries comprising binding agents, whereby a free-flowing mass is produced. A green body is produced from the mass by means of powder injection moulding. A portion of the auxiliaries is extracted by heating the green body in a container and exposing said body to a stream of solvents. The green body is sintered, whereby the component is produced. The aim of the invention is to enable fast and gentle extraction for releasing green bodies which are produced by means of powder injection moulding. According to the invention, the extraction comprises a heating-up phase during which the temperature of the green body is permanently or gradually increased and the green body is overflown by solvent in the form of a compressed, supercritical treatment gas.

Abstract: The invention relates to a method and an installation for processing thermoplastic synthetic materials. According to the invention, the melt strands or the like are displaced in oscillation or pulsation in order to indent or penetrate the joint lines between at least two injection strands.

Abstract: An injection molded resin gear 1 includes a rim 4, a hub 3 and a web 5 which connects the rim 4 to the hub 3. A plurality of ribs 7 for guiding a molten resin, which is injected from pin point gates 8, to the hub 3 protrude from the outer periphery of the hub 3 on one side of the web 5 so as to correspond to the pin point gates 8. The ribs 7 are formed so as to be recessed from the side face 10 of the hub 3. In the connecting portions of the ribs 7 to the hub 3, fillet portions 12 are formed for smoothly guiding the flow of the resin from the hub 3 toward the web 5 when the injection molded resin gear 1 is formed.

Abstract: A colorization pellet includes a pellet body formed of a material having a predetermined color and a plurality of fibers in the pellet body. A plurality of reflective devices are attached to the fibers whereby when the colorization pellet is combined with a plastic molding compound during an injection molding process to form a part, the formed part has a metallic appearance.

Abstract: A method for compounding gel-free injection molding feed stock for injection molding net-shape ceramic parts, including the steps of: mixing inorganic particles with non-gel forming water soluble organic binders having molecular weight between 1000 and 1,000,000 and that are between 0.5 weight % and 10 weight % based upon the inorganic particles, along with plasticizers, water and processing aids in a mixer to form a mixture, wherein the non-gel forming water soluble organic binders are composed of high and low molecular weight organic binders; compounding the mixed inorganic particles and the non-gel forming water soluble organic binders at a high temperature in the range of between 70° and 98° Centigrade, under shear force, to form a homogenous viscous slurry in the range of 5×103 and 7×104 Pa.sec at a shear rate of 10 sec?1; cooling the homogenous viscous slurry to room temperature to form a compounded solid mass.

Abstract: A method for fabricating a mold for a light guide plate in accordance with the present invention generally includes the following steps: providing a substrate (18); and providing electron beams (15) to etch the substrate according to predetermined patterns. Because a focus diameter of the electron beams is adjustable, a very narrow line-width of the patterns can be obtained by employing the fine focus diameter of the electron beams. That is, the mold (18′) fabricated by the present invention can have fine patterns at the nanoscale level. The light guide plate (22) formed using the mold has correspondingly fine patterns. These fine patterns can greatly enhance the quality and performance of the light guide plate.

Abstract: An injection mould which comprises at least five modules aligned with each other. The five modules correspond to a first mould module and a second mould module to form a product cavity, a drive module for driving of sliders, an engaging module adapted, by application of a force, to prevent dividing between the first and the second mould module when introducing product material into the product cavity, and an ejector module for ejecting a completed product from one of the first and the second mould module. The method for making injection moulds comprises the steps of receiving a product pattern, defining function holes and function recesses, and defining, separate from and parallel to the construction of function holes and function recesses, a product cavity and the parting plane of the mould. Moreover the method comprises the step of mechanically machining a plurality of modules essentially simultaneously.

Abstract: A method for casting Y2O3 has steps of adding an acid to a slurry comprising at least a ceramic material having a purity of an Y2O3 being 99 wt % or more with an average particle diameter of 2 &mgr;m or less, water, a binder and a dispersant so that a pH value can be adjusted ranging from 8.5 to 10.5 and injecting the slurry into a mold.

Abstract: The compression molded article includes an outer plastic film layer, a first plastic layer adhered to the outer plastic film layer and a second plastic layer adhered to the first plastic layer. Long fibers having a length of from 8 to 100 mm are admixed with the second plastic layer. The article is formed by compression molding.

Abstract: A method is provided for forming a body for a hard disk carriage assembly from polyphenylene sulfide 40% glass fill. An injection mold is heated to approximately 130° C.; then a volume of polyphenylene sulfide 40% glass fill is injected into the mold to form the body of the carriage assembly. The polyphenylene sulfide 40% glass fill is then cooled within the mold for approximately 45 seconds before the body is ejected from the mold cavity. The body is then heated to approximately 130° C. for at least 2 hours in a post-bake operation.

Abstract: A multilayer ceramic composite is described which contains at least one supporting zone having oxidation-sensitive reinforcing fibers as well as a matrix. The matrix optionally contains oxidation-sensitive components. The composite further contains at least one surface layer, as well as at least one additional protective layer disposed between the supporting zone and surface layer, and whose matrix is composed substantially of at least one component of the matrix of the supporting zone or cover layer. The protective layer further contains additives that form self-healing layers.

Abstract: A composite molding compound comprising a combination of metal and ceramic powders is disclosed. The powders are combined with a binder, a liquid carrier and other processing additives in a manner to provide uniform distribution of two phases in a material format that facilitates the molding of complex parts at relatively low pressures and temperatures using conventional injection molding machines. The products formed from these molding compounds may be designed with tailored physical and mechanical properties such as thermal conductivity, thermal expansion coefficient, density, elastic modulus and wear properties.

Abstract: X-ray imageable articles, for instance surgical implements or parts therefore which are used in minimally invasive surgical procedures, may be prepared by a process including the steps of: (a) preparing a mixture composition comprising: i) radiolucent particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having a particulate size of no more than 40 microns, ii) radiopaque particulate material selected from ceramic materials, metallurgic materials, and combinations thereof and having a particulate size of no more than 40 microns, and (iii) at least one polymeric binder material; (b) injection molding the mixture composition into a preform; (c) optionally removing the binder material from the preform; and (d) sintering the preform.

Abstract: An improved porous article and a method for forming such porous article are provided. A mixture of ceramic or metal particles and pliable organic hollow spheres is prepared in a liquid, typically as a suspension. The article is formed by pressing, slip casting, extruding or injection molding the mixture. The article is dried to remove the liquid, and then is fired so that the particles are bonded such as by sintering, and the organic spheres are eliminated, resulting in a strong porous article having uniformly spaced interconnected voids.

Abstract: A composite molding compound comprising a combination of metal and ceramic powders is disclosed. The powders are combined with a binder, a liquid carrier and other processing additives in a manner to provide uniform distribution of two phases in a material format that facilitates the molding of complex parts at relatively low pressures and temperatures using conventional injection molding machines. The products formed from these molding compounds may be designed with tailored physical and mechanical properties such as thermal conductivity, thermal expansion coefficient, density, elastic modulus and wear properties.

Abstract: To form an arc tube body including a main tube portion to be a discharge space and thin tube portions for accommodating electrodes, a core (6) is disposed in a hollow space formed by a pair of arc tube body formation molds (7) and (8) and thereafter, a slurry (12) is injected into a space between the molds (7), (8) and the core (6). In the core (6), portions for forming the internal shape of the thin tube portions of the arc tube body are provided with a shaft (3).

Abstract: The present invention relates to a method of fabricating a micro device and a method for manufacturing a mold for molding the micro device.

Abstract: A method for forming composite parts of two or more dissimilar materials by injection molding. Two or more different metallic- or ceramic-based powder materials are used to form two or more different feedstocks, which are each melted and injected under heat and pressure into mold cavities and allowed to solidify to form a composite green compact. In an example of the present invention, two or more powder materials are each mixed with a binder system and granulated to form feedstocks, the feedstocks are melted and concurrently or sequentially injected into a mold and allowed to solidify, and the solidified composite green compact is then subjected to binder removal and sintering processes.

Abstract: Flat strip lamella for reinforcing weight-carrying or weight-transferring building components. It has a composite structure consisting of a plurality of pliant or loose-flex supporting fibers (26) aligned parallel to each other, and a binding matrix (28) which connects the supporting fibers to each other so that they are shear-resistant, and is fastenable by means of an adhesive (16) by its broad side to the surface of the building component (12) that is to be reinforced. So that the flat strip lamella, to which the binding matrix gives rigid elastic form, can also be bent over corner edges of a building component (12), the invention proposes that the binding matrix (28) be removed, in at least an intermediary area (30), by uncovering the supporting fibers (26), and that the uncovered supporting fibers be subjected to a liquid or pasty thermosetting plastic, in order to stabilize the bent-over condition.

Abstract: The present invention relates to a multiple foam substrate of predetermined shape and a method of manufacturing the substrate. The substrate is a multiple foam substrate which may be manufactured by the method with a mold having first and second mold cavities. The method includes injecting a first foam into the first mold cavity sufficiently to fill the first mold cavity and storing the first foam in the first mold cavity for a predetermined time sufficient to form a substantially non-mixing surface on the first foam. The method further includes injecting a second foam into the second mold cavity and onto the non-mixing surface on the first foam sufficiently to fill the second mold cavity. The method further includes storing the second foam in the second mold cavity for a predetermined time sufficient to bond the first foam to the second foam along the non-mixing surface.

Abstract: Reinforcing textile sheets (10, 11, 12, 16, 17) are superposed on mandrels (9, 14 and 15). The reinforcing textile sheets superposed on the mandrels are placed in a closed jig (2, 3). A thermosetting resin is introduced into the closed jig to impregnate the superposed reinforcing textile sheets. The thermosetting resin impregnated into the superposed reinforcing textile sheets is made to half-set in the closed jig to form a half-set composite material wing component member including a rear spar, ribs, an upper skin and a lower skin. The half-set composite material wing component member is taken out of the jig and the mandrel is removed from the half-set composite material wing component member. The half-set composite material wing component member and a half-set front spar are bonded together with an adhesive to form a half-set wing structure. The half-set wing structure is subjected to a high-temperature setting process to set the wing structure and the adhesive simultaneously.

Abstract: A method for manufacturing an artificial reef based on industrial waste is disclosed. Industrial wastes, including red mud, blast furnace slag, the sludges from the factories of refining raw ore, broken pieces of glass, the stone powders from the anti-pollution facilities equipped in stone- or aggregate-extracting spots, the slurries from the terminal treatment plants of water and sewage, the ashes from the incinerators for household wastes, the pulp sludges and slurries from paper mills, the coal ashes from thermoelectric power plants, and the side-products produced upon coal mining, are utilized, alone or in combination with a plasticizer and a mineralizer, in constructing artificial fishing reeves through pug-milling, molding and thermal treatment processes. The artificial fishing reef, through which the industrial wastes are converted into environment-affinitive resources, have advantages of being economically favorable and producing no pollution of the environment.

Abstract: A powder injection molding process involves providing a melt mixture that includes a powder and a binder. The melt mixture is pressurized in an injection molding machine and a gas is injected into the melt mixture. The melt mixture and gas are injected into at least one mold to form a green part and the binder is removed from the green part.

Abstract: A method of removing substantially all of the volatile component in a green, volatile-containing ceramic article is disclosed. The method comprises freezing the ceramic article; and then subjecting the frozen article to a vacuum for a sufficient time to freeze-dry the article. Frequently, the article is heated while being freeze-dried. Use of this method efficiently reduces the propensity for any warpage of the article. The article is often formed from a ceramic slurry in a gel-casting process. A method for fabricating a ceramic core used in investment casting is also described.

Abstract: The invention relates to a method of forming a composite article comprising the steps of forming a plurality of green ceramic elements, wherein the green ceramic elements are arranged side by side, and the green ceramic elements are spaced from each other by gaps; filling the gaps with a second material; and sintering the green ceramic elements with the second material to form the composite article. The second material, after being sintered, acts as a reflector layer to prevent substantially all light in one of the sintered ceramic elements from reaching an adjacent sintered ceramic element. The step of filling the gaps may be carried out by forming a slurry containing the second material in powder form and immersing the green ceramic elements in the slurry. The process of cosintering the green ceramic elements with the reflector composition provides improved dimensional control during sintering and reduces processing costs.

Abstract: The invention utilizes green support structures during sintering to maintain the shape, reduce sagging and prevent separate part sections from coming into contact and fusing together during the sintering process. In the most preferred embodiment, monolithic green structures are form with integrated support green structures that are released from the parts after sintering. Preferably monolithic green structures are formed by the Mold Shape Deposition Manufacturing (Mold SDM) process. By the method described, complex sintered structures can be made having interlocking and independently movable interlocking parts.

Abstract: A method for compounding gel-free injection molding feed stock for injection molding net-shape ceramic parts, including the steps of: mixing inorganic particles with non-gel forming water soluble organic binders having molecular weight between 1000 and 1,000,000 and that are between 0.5 weight % and 10 weight % based upon the inorganic particles, along with plasticizers, water and processing aids in a mixer to form a mixture, wherein the non-gel forming water soluble organic binders are composed of high and low molecular weight organic binders; compounding the mixed inorganic particles and the non-gel forming water soluble organic binders at a high temperature in the range of between 70° and 98° Centigrade, under shear force, to form a homogenous viscous slurry in the range of 5×103 and 7×104 Pa. sec at a shear rate of 10 sec−1; cooling the homogenous viscous slurry to room temperature to form a compounded solid mass.

Abstract: Molded green parts are fused together to form a bond or joint during the sintering process. The molded green parts are held in intimate contact with each other and sintered at temperatures sufficient to fuse the parts together. The process may entail dry fusing of part-to-part or it may include the use of a flux between the parts being fused together to enhance the bond.

Abstract: Target velocity data D14 specifying injection operation required for a injection cylinder unit is set in advance, the injection operation is performed actually, command data D17 given to the injection cylinder unit during the injection operation and detected velocity data D15 indicating the operation performed by the injection cylinder unit are recorded, correction value data D18 is calculated from a difference between the detected velocity data D15 and the target velocity data D14 to correct the command data D17 of the previous injection operation by using the correction value, auxiliary amplifier command data D19 is generated as the command data for the next injection operation, and the injection cylinder unit is operated by giving the generated auxiliary amplifier command data at the time of the next injection operation.

Abstract: A powder injection molding and infiltration process. A powder of a skeleton material having a relatively high melting point is mixed with a composite binder to form a mold mixture. The composite binder is comprised of at least two binder materials. The mold mixture is molded into a desired shape in a mold device to produce a molded part. The composite binder is then removed to produce voids in the molded part and the voids are filled by infiltrating an infiltrant comprised of an infiltrant material having a relatively low melting point to produce a composite molded part. In a preferred embodiment the skeleton material is TiB2 and the infiltrant material is aluminum and the composite binder is comprised of a plastic and a wax. In this embodiment the wax portion of the composite binder is removed using a solvent and the plastic is removed during the infiltration step. The resulting composite part has a TiB2 skeleton with voids substantially filled with aluminum.

Abstract: A method is proposed for manufacturing a pin heater that has a substantially internal insulating layer and an external conductive layer, the two layers composed of a ceramic composite structure, wherein before the pin heater is sintered, its shaping is accomplished by way of the ceramic injection molding technique or by cold combined axial/isostatic pressing.

Abstract: A method of a fabricating silica glass by sol-gel process is provided. The method includes mixing silica, a binder, a dispersing agent and a gelling agent, and forming a sol without air bubbles; injecting the sol into a mold, the injection of the sol into the mold being controlled by the pressure of an inert gas; gelating the sol injected into the mold and demolding the gel; and drying the demolded gel, and thermally-treating the dried gel. Therefore, incorporation of impurities and air bubbles during injection of a sol into a mold is minimized, and injection amount and injection rate of the sol can be controlled.

Abstract: A method of a fabricating silica glass by sol-gel process is provided. The method includes mixing silica, a binder, a dispersing agent and a gelling agent, and forming a sol without air bubbles; injecting the sol into a mold, the injection of the sol into the mold being controlled by the pressure of an inert gas; gelating the sol injected into the mold and demolding the gel; and drying the demolded gel, and thermally-treating the dried gel. Therefore, incorporation of impurities and air bubbles during injection of a sol into a mold is minimized, and injection amount and injection rate of the sol can be controlled.

Abstract: A method for manufacturing the roller carrier of a vibration balance device, the roller carrier is installed with at least one round track around a rotary axis thereof for carrying a plurality of rollers; characterized in that: the roller carrier is made of ceramic powder and made by a process of ceramic powder metallurgy. The material of the powder is A92A aluminum oxide or zirconium oxide, or other proper metal oxide. The manufacturing process of the ceramic powder metallurgy includes the steps of: feeding material, compacting, sintering, and polishing, or other manufacturing process of the ceramic powder metallurgy can be used, which includes the steps of feeding material, pelletizing, injection molding, debinding, sintering, and polishing. The roller carrier from aforementioned processes uses less materials, can be mass-produced, has a precise dimension, is light weighted, has a smooth surface and has a high surface hardness.