Abstract: A sheet material comprises a recessed part and a non-recessed part which are formed on a surface side of a cushion base material. The sheet material comprises a gradual changing part in which a height H changes gradually across the recessed part and the non-recessed part. The sheet material may comprise an obtuse angle face portion formed on a near part to a bottom of the recessed part which comprises a wide angle face portion formed on a near part to the non-recessed part. In a producing method of the sheet material, an embossing mold material comprises an embossing gradual changing part in which a depth D changes gradually across an embossing projected part and an embossing non-projected part. The embossing mold material is pressed in a situation where the embossing projected part and the embossing gradual changing part are abutting to a surface side of a cushion base material.

Abstract: A panel heater comprising, on an upper surface of a metallic sheet (2) provided with PTC ceramics (1) on the back side thereof, a highly insulating material or an open space (4) at the portion corresponding to the back side portion to which the PTC ceramics are provided, with a material (3) for conducting heat from the metallic sheet being thus provided to the rest of the surface side of said metallic sheet, and a finishing sheet (5) being established on the upper surface of the whole structure. More preferably, the metallic sheet (2) is provided with equally spaced concave grooves with PTC ceramics (1) on the back plane of said grooves and a highly insulating material or an open space (4) inside said grooves, and a finishing sheet (5) established thereon. Accordingly, a simply structured panel heater resistant to heavy loads yet free from local overheating is provided.

Abstract: A material for a magnetic head slider consists essentially of 0.1 to 20.0 vol % of at least one of oxides the group Va elements of the International Periodic Table (Ta, Nb, V) and 80.0 to 99.9 vol % of stabilized cubic ZrO.sub.2 containing a stabilizer (Y.sub.2 O.sub.3, MgO, CeO.sub.2). It has improved precision machinability, machining efficiency, high strength, densified structure, affinity with the recording medium or lubricity, besides wear resistance. It may be machined precisely into a thin film magnetic head slider with a reduced amount of chipping.

Abstract: A sintered material for recording/reading (particularly magnetic) head slider is produced by:preparing a powdery mixture which comprises 0.5 to 6.0% by weight of at least one component selected from the component group A consisting of the following elements and compounds thereof, a garnet type compound consisting essentially of erbium oxide and aluminum oxide in amounts of 2 to 12% by weight and 0 (exclusive) to 2 (inclusive) % by weight based on the total composition, respectively, and expressed by the formula Er.sub.3 (Al,Er).sub.2 (AlO.sub.4).sub.3 through (Er, Al).sub.3 Al.sub.2 (AlO.sub.4).sub.3, and the balance being silicon carbide powder:the elements for the component group A being Ti, V, Cr, Mn, Mg, Y, Zr, Nb, Mo, Ba, La, Ce, Gd, Hf, Ta, W, Th, and Cs; andsintering the resultant mass under the application of a high pressure.Further sintering aids of Be, BeO, B and B.sub.4 C may be present. For the garnet type compound, erbium oxide may be used, preferably in combination with alumina.

Abstract: The deterioration of strength at high temperature of Si.sub.3 N.sub.4 --Y.sub.2 O.sub.3 --AlN series silicon nitride-type sintered bodies is reduced by employing Y.sub.2 O.sub.3 --MgO--AlN series as a sintering aid wherein the stoichiometrical ratio of Y, Mg and Al in the sintered body is controlled to a specific range, thereby decreasing the glass phase to decrease deterioration of strength at high temperatures. Assuming Y as A.sub.1 mol, Mg as B.sub.1 mol and A.sub.1 as C.sub.1 mol based on one mol of Si.sub.3 N.sub.4 in the sintered body, the specific range, wherein each of A.sub.1, B.sub.1 and C.sub.1 is not less than 0, satisifies the conditions: ##EQU1## and the crystal phase of Si.sub.3 N.sub.4 consisting of an .alpha.-Si.sub.3 N.sub.4 phase in which a part of Si.sub.3 N.sub.4 is replaced by Y, Mg, O and Al, and a .beta.-Si.sub.3 N.sub.4 phase in which a part of Si.sub.3 N.sub.

Abstract: A material for thin film magnetic head slider particularly suited for high recording, which is obtained by sintering a mixture consisting essentially of:5 to 45% by weight of titanium carbide component;0.2 to 10% by weight of zirconium oxide;0.05 to 2% by weight of oxide of yttrium;0.2 to 25% by weight of aluminum nitride; and the balance of Al.sub.2 O.sub.3 component substituted with 0.5 to 8% by weight being at least one machinability agent selected from the group consisting of oxides of Mg, Ca, B, Ni and Cr and complex oxides thereof.

Abstract: A sintered article of silicon carbide containing 2 to 12% by weight of erbium oxide, not more than 2% by weight of aluminum oxide, existing in the form of a composite oxide exhibits remarkable characteristics in resisting to oxidation, thermal shock and corrosion, and shows increased strength at elevated temperatures due to their effect to compaction of resulting structure of the sintered article due to retaining fineness of crystal grains. Those meritorious effects can be enhanced by adding to the aforementioned composition 0.5 to 6.0% by weight of at least one element selected from among titanium, vanadium, chromium, manganese, magnesium, yttrium, zirconium, niobium, molybdenum, barium, lanthanum, cerium, gadolinium, hafnium, tantalum, tungsten, thorium, and cesium or a compound of this element.

Abstract: A sintered material for recording/reading (particularly magnetic) head slider is produced by:preparing a powdery mixture which comprises 0.5 to 6.0% by weight of at least one component selected from the component group A consisting of the following elements and compounds thereof, a garnet type compound consisting essentially of erbium oxide and aluminum oxide in amounts of 2 to 12% by weight and 0 (exclusive) to 2 (inclusive) % by weight based on the total composition, respectively, and expressed by the formula Er.sub.3 (Al,Er).sub.2 (AlO.sub.4).sub.3 through (Er,Al).sub.3 Al.sub.2 (AlO.sub.4).sub.3, and the balance being silicon carbide powder:the elements for the component group A being Ti, V, Cr, Mn, Mg, Y, Zr, Nb, Mo, Ba, La, Ce, Gd, Hf, Ta, W, Th, and Cs; andsintering the resultant mass under the application of a high pressure.Further sintering aids of Be, BeO, B and B.sub.4 C may be present. For the garnet type compound, erbium oxide may be used, preferably in combination with alumina.

Abstract: A magnetic head slider and a material for it which comprises a sintered body obtained by sintering a raw material powder composed of 65 to 90% by weight of ZrO.sub.2 component containing therein a stabilizer and the balance of Al.sub.2 O.sub.3 component, 2% by weight or below of which has been substituted with a binder. The stabilizer is Y.sub.2 O.sub.3, MgO or CeO and the binder is Y.sub.2 O.sub.3 or MgO.

Abstract: A recording head slider comprises a slider body having a fluid bearing surface on a primary surface thereof and at least one transducer on at least one side of the slider body, the slider body being made of a sintered body produced by sintering a base composition consisting essentially of 10-40 percent by volume of silicon carbide and the balance being alumina. The base composition may comprise 0.2-10 percent by weight of sintering aids MgO, Y.sub.2 O.sub.3, ZrO.sub.2, CaO, Er.sub.2 O.sub.3 and Cr.sub.2 O.sub.3. This slider has high precision machinability and compatibility with recording media.

Abstract: An alumina base substrate material for recording heads, which comprises a densely sintered body consisting essentially of:per 100 parts by weight of a base component of 30 to 40% by weight of a titanium compound having TiO.sub.2 to (TiC+TiO.sub.2) percentage of 5 to 15% by weight and the balance being Al.sub.2 O.sub.3,components A, B and C, provided that the A to B ratio is within a hatched KLMN area in FIG. 1, in the following given parts by weight, andoxidic impurities in amounts of no higher than 0.2% by weight based on the total composition,said sintered body having an average crystal grain size of no higher than 1.3 microns, a porosity per area of no higher than 0.5%, a bending strength of at least 70 kg/cm.sup.2 and a hardness H.sub.R A of at least 93.0: whereincomponent A is at least one of spinels expressed by RO-Al.sub.2 O.sub.3, where R is at least one of Mg, Mn, Ni and Co, in an amount of 2.0 to 17.5 parts by weight,component B is 0.2 to 2.0 parts by weight of ZrO.sub.2, andComponent C is 0.

Abstract: Aluminum oxide substrate material for magnetic heads having improved toughness consisting essentially of: (1) 100 parts by weight, consisting of aluminum oxide and 30 to 50 parts by weight of (TiC+TiO.sub.2), and that provided TiO.sub.2 /(TiC+TiO.sub.2).times.100=5 to 15, (2) 0.5 to 5 parts by weight of addition of free cutting comprising at least one from the group of MgO, NiO, Cr.sub.2 O.sub.3 and ZrO.sub.2, and (3) 0.05 to 2 parts by weight of Y.sub.2 O.sub.3.The method of hot-forming aluminum oxide substrate material for magnetic head having improved sinterability consisting of (a) preparing a green compact by molding a raw material mixture which contains: (1) 100 parts by weight, consisting of aluminum oxide and 30 to 50 percent by weight of (TiC+TiO.sub.2), and that provided TiO.sub.2 /(TiC+TiO.sub.2).times.100=5 to 15, (2) 0.5 to 5 parts by weight of machinability agents comprising at least one from the group of MgO, NiO, Cr.sub.2 O.sub.3 and ZrO.sub.2, and (3) 0.05 to 2 parts by weight of Y.sub.2 O.

Abstract: This invention discloses zirconia-containing grinding media in the preparation of magnetic disc coating and method for producing such grinding media. The grinding media essentially consists of zirconia-sintered body containing 3.6% to 8.0% by weight of yttrium oxide, the zirconia sintered body having a means grain size of less than 2 .mu.m and the relative theoretical density of more than 98.0%.

Abstract: A material for magnetic head sliders comprises a mixed powder consisting of 40 to 80% by weight of Al.sub.2 O.sub.3 and 20 to 60% by weight of TiO.sub.2, and further contains, per 100 parts by weight of the Al.sub.2 O.sub.3 and TiO.sub.2 mixture, 0.5 to 5 parts by weight of at least one of CaO, MgO and Y.sub.2 O.sub.3, and 0.5 to 10 parts by weight of ZrO.sub.2.

Abstract: Sintered bodies having improved sinterability and toughness consist essentially of: (1) 100 parts by weight of titanium carbide, titanium oxide and aluminum oxide, the titanium carbide and titanium oxide accounting for 15 to 60 percent by weight and the aluminum oxide accounting for 85 to 40 percent by weight, the amount of titanium oxide relative to the titanium carbide and titanium oxide being 5 to 15 percent by weight, and (2) 0.039 to 1.575 parts by weight of yttrium. Sintering aids may include at least one of the oxides of magnesium, nickel, molybdenum, chromium, cobalt, iron and manganese.

Abstract: The powder mixture consisting of 0.5 to 5 percent by weight of TiN and 99.5 to 95 percent by weight of Al.sub.2 O.sub.3 is first presintered and is subsequently subjected to a hot isostatic pressing so as to produce a sintered product which has the maximum grain size of 2 .mu.m and the hardness of more than H.sub.R A 94.Such sintered product is used as a cutting tool for a high-speed continuous cutting operation.

Abstract: A new hot isostatic pressing method produces sintered material having a very fine structure as well as uniform properties by forming a unique capsule such as a titanium capsule of metal over a presintered material for sintering a ceramic cutting tool material is disclosed.

Abstract: Sintering of a mixture of alumina and titanium carbide has been difficult heretofore, but by the intermediary action of titanium oxides, sintering of a powder mixture consisting of alumina and titanium carbide by hot-pressing at a comparatively lower temperature than that used in conventional processes becomes possible. Various procedures in which the above principle is applied, the powder mixture to be used therein and the materials produced thereby which are to be used for manuacturing cutting tools are disclosed.