An abrasive article includes an abrasive particulate material made of alumina crystals and a primary additive composition impregnated within the abrasive particulate material, the primary additive composition including a combination of Mg and Ca, wherein Mg and Ca are present in an additive ratio [Mg:Ca] within a range between about 1:1 and about 10:1, and further comprising at least about 0.2 wt% Ca for the total weight of the abrasive particulate material..

Abrasive articles including abrasive particulate materials, coated abrasives using the abrasive particulate materials and methods of forming

The invention relates to a hydraulically and chemically bonding refractory cement, which comprises a caustic magnesia component having a BET specific surface area of at least 0.5 m 2 /g, and a carboxylic acid component, wherein the carboxylic acid component consists of at least one carboxylic acid that is only slightly water soluble and/or has a low dissolution rate in aqueous solutions, and which carboxylic acid component is capable of generating at least one soluble magnesium salt upon contact of said cement with water. The invention further relates to a corresponding refractory material containing the magnesia cement and to uses thereof for the manufacture of products useful in various industries.

Refractory magnesia cement

The invention provides a metal bonding agent diamond grinding tool. The metal bonding agent diamond grinding tool comprises, by mass, 70%-90% of a metal matrix and the balance abrasive particles. The invention further provides a manufacturing method for the metal bonding agent diamond grinding tool. The metal bonding agent diamond grinding tool is small in abrasion, high in grinding efficiency and long in service life, can be used for coarse grinding and medium grinding and can also be used for accurate grinding and polishing machining.

Metal bonding agent diamond grinding tool and manufacturing method thereof

The invention discloses a testing machine of an interface pressure of a cable accessory, wherein the testing machine is used for measuring an interface pressure after installation of a cable accessory. The testing machine is composed of a measurement control unit, an expanding head unit, a moving unit, a moving power unit and a machine body; and all unit components are arranged on the machine body. The moving unit is used for placing a to-be-tested cable accessory product; and the moving power unit is used for driving the moving unit, so that that the moving unit and the cable accessory product can be driven to make linear movement. The axial direction of the cable accessory product after being placed is parallel to the moving direction of the moving unit. The expanding head unit is arranged on a linear moving track of the moving unit; the axis of the expanding head unit is superposed with the linear moving track of the moving unit; and a pressure sensor is arranged on the outer surface of the expanding head unit. The pressure sensor connected with the measurement control unit is used for collecting and analyzing a strain signal of the pressure sensor and outputting an interface pressure testing result. The provided testing machine has advantages of reasonable structure, convenient operation, high automation and modularization, and high testing precision.

Testing machine of interface pressure of cable accessory

The utility model discloses a soil pressure and grouting pressure sensor of a shield tunneling machine. The soil pressure and grouting pressure sensor comprises a housing 12, an outer tube 16 connected with the housing 12 and an electrical connector 21 connected with the outer tube 16, wherein a main force bearing body 11 transfers force to a force bearing element 24, the force bearing element 24 transfers the force to a second pressure detection unit 25, the second pressure detection unit 25 is connected with a second circuit board 17 through a sensor lead wire 19, the circuit board is connected with a signal output unit 10, and the signal output unit 10 is connected with the electrical connector 21 through a circuit connecting wire 20. According to the utility model, a novel pressure sensitive material is adopted to form a new circuit, and the main force bearing element, the force transfer part and a main elastic body are in rigid connection (actually connected into a whole), so that the soil pressure and grouting pressure sensor of the shield tunneling machine is good force bearing and resetting, is pollution-free and has long service life.

Soil pressure and grouting pressure sensor for shield tunnelling machine

PROBLEM TO BE SOLVED: To accurately measure earth pressure even without increasing the mechanical assembly accuracy of an earth pressure meter by providing a pressure reception part and a pressure detection part. SOLUTION: When such pressure as earth pressure is applied to the entire surface of a pressure reception part 5 vertically, the pressure reception part 5 is recessed along an axial line L of a case body 3, thus shifting the short sides of a pressure detection part 12 mutually in parallel direction and hence curving a distorted part. The amount of distortion is transferred to a strain gauge 4 and is taken out externally from a cable 20 as an electrical signal corresponding to the amount of distortion. Even if such pressure as earth and sand is applied to the pressure reception part 5 in cantilever type, the reception part 5 vertically drops along the body 3 so that the detection part 12 is distorted and a strain gauge 14 can accurately detect the earth pressure. Also, a load cell for constituting the detection part 12 has a high sensitivity and improved linearity and is less subjected to the influence of an eccentric load.

Earth pressure meter

PROBLEM TO BE SOLVED: To provide a chuck device which is capable of promptly and surely chucking a test piece and improves durability, and a material testing machine with the same.SOLUTION: A chuck device comprises a chuck body 100, a pair of clamping plates 200 holding a test piece therebetween, and clamping plate opening/closing means 300 which opens/closes the clamping plates. In the clamping plate opening/closing means, a screw part is formed. The chuck body includes a mounting frame 110 to which the clamping plate opening/closing means is mounted and in which the pair of clamping plates are disposed while being confronted via the clamping plate opening/closing means. The screw part in the clamping plate opening/closing means is threaded into a screw hole of the mounting frame, such that the clamping plates are moved to be opened/closed and the test piece is held between the clamping plates. In the vicinity of a distal end portion of the clamping plate opening/closing means, an annular groove part 340 is formed. The distal end portion of the clamping plate opening/closing means is connected to an opening on one end face of each clamping plate to perform idling, a rod-like member is inserted to an insertion hole provided on a side face of the clamping plate, and engaged into the groove, thereby preventing the clamping plate from being removed from the clamping plate opening/closing means. In the mounting frame, a frame part bent inwardly is formed and the clamping plate is abutted with the frame part in a slidable manner.

Chuck device and material testing machine with the chuck device

PROBLEM TO BE SOLVED: To eliminate the need for a reducing atmosphere and an inert atmo sphere even when diamond ultra-fine abrasives are sintered without being oxi dized by including specific parts by weight of SiO2 , Al2 O3 , B2 O3 , etc. SOLUTION: This binder for a vitrified grinding wheel is composed of 47 to 53 parts by weight of SiO2 , 17 to 23 parts by weight of Al2 O3 , 9 to 15 parts by weight of B2 O3 , 6 to 14 parts by weight of (CaO+MgO), and 4 to 16 parts by weight of (K2 O+Na2 O+Li2 O). The SiO2 , Al2 O3 , B2 O3 , CaO, MgO, K2 O, Na2 O, and Li2 O can be used in the form of raw materials similar to raw materials used in the manufacture of glass, etc. These components are mixed in a desired ratio, baked at high temperatures for vitrification, and crushed to obtain the binder. The binder for the vitrified grinding wheel enables manufacture of a good vitrified grinding wheel even if the temperature at which the binder mixed with abrasives is sintered is not more than 720 deg.C. The sintering temperature is preferably 680 deg.C or more.

Binder for vitrified grinding wheel, manufacture of vitrified grinding wheel using the binder, and vitrified grinding wheel

PURPOSE:To provide a cement grinding stone for dental purpose which has a high water resistance strength and does not produce free chloride which causes rust by mixing grinding material and powders of polyacrylic acid and magnesium oxide, forming the mixture into a desired shape and curing the same. CONSTITUTION:The cement binder used for the grinding stone is a mixture of viscous water solution of polyacrylic acid having an average molecular weight of 30,000-60,000 and powder of magnesium oxide in the weight ratio of 1:3, the structural formula is shown in the appended drawing. The polyacrylic acid forms chelate bonds with the molecules bridged by magnesium and sets with macromolecules to provide a high mechanical strength which is suitable as a binding agent of grinding stones.

Miyazaki Hisamitsu

Papers

Earth pressure meter

Chuck device and material testing machine with the chuck device

Binder for vitrified grinding wheel, manufacture of vitrified grinding wheel using the binder, and vitrified grinding wheel

Magnesia carboxylate cement grinding stone