Abstract: Sealing a thermal spray coating with an extensively diluted sealant, such as a thermosetting epoxy resin, allows the sealant to more effectively protect the coating against leakage, wear and corrosion. The dilution of the sealant is believed to enhance penetration of the sealant into the coating. Such sealed coatings are useful in oilfield applications.

Abstract: A method and apparatus for notifying a receiving device of fault conditions in a sensing element or an instrument. The instrument generates an analog signal that has an amplitude which is representative of a variable. The analog signal amplitude has a range defined by a lower limit and an upper limit. The instrument transmits the analog signal to the receiving device. When the instrument detects a fault condition in itself or in the sensing element, the transmitter periodically changes the analog signal amplitude by a predetermined amplitude for as long as the fault condition exists. The predetermined amplitude and its polarity are such that the amplitude of the periodically changed analog signal lies within the range. The receiving device generates an alarm when it detects the pulses.

Abstract: An electrochemical sensor wherein an ion impermeable plug is interposed between the adjacent faces of the large plugs that are used in the salt bridge. The salt bridge also includes a solid cylindrical plug that passes through the ion impermeable plug to thereby interconnect the adjacent large plugs. The large plugs have a central bore for receiving the glass sense electrode. The impermeable plug has protrusions to provide a better seal between the impermeable plug and the glass sense electrode and the impermeable plug and the housing in which the salt bridge is inserted. In addition, the sensor may also include a rigid liner between the large plugs and the glass sense electrode to act as a barrier to prevent damage to this sense electrode during and after impregnation.

Abstract: A method for forming a ring structure having a high volume fraction of a filament reinforcement within a metal matrix is disclosed. The ring structure is formed by consolidating a set of nested rings each of which has a high volume fraction of the filamentary reinforcement therein. The nesting is done to provide a clearance between the rings of the nest of about 2 or 3 mils. The nested rings are enclosed within a HIPing can and the structure is HIPed at about 15 ksi and 1000.degree. C. for over an hour. A single superring structure results from the HIPing.

Abstract: A high strength panel-like structure having a high strength to weight ratio. The structure comprises two integrally formed panel sections, each panel section comprising an outer sheet portion and inwardly extending ribs that are formed integrally with the related sheet portions, and having inner bonding surfaces spaced from their respective sheet portions. The two panel sections are formed into a unitary structure by bonding the two sections at the bonding surfaces of the ribs. Thus, the bonding area of the panel structure is at the neutral axis of the structure. Desirably inner bonding surfaces of the ribs have a width dimension greater than a width dimension of the ribs.

Abstract: A method for forming a ring structure having a high volume fraction of a filament reinforcement within a metal matrix is disclosed. The ring structure is formed by consolidating a set of nested rings each of which has a high volume fraction of the filamentary reinforcement therein. The nesting is done to provide a clearance between the rings of the nest of about 2 or 3 mils. The nested rings are enclosed within a HIPing can and the structure is HIPed at about 15 ksi and 1000.degree. C. for over an hour. A single superring structure results from the HIPing.

Abstract: A method of altering the crystal form of an alloy is disclosed. To accomplish this change in crystal form, the concentrations of the more volatile constituents of the alloy are reduced and the concentration of the less volatile constituents is increased on a relative basis. The process may be carried out in forming a reinforced structure. For this purpose, an improved reinforced matrix and a method of forming it are taught. The reinforcement may be silicon carbide filaments or other reinforcing filaments. The matrix is a titanium 1421 alloy nominally containing 14 weight percent of aluminum and 21 weight percent of niobium. The matrix is formed by plasma-spray forming a powder of the alloy to impart to the alloy particles a superheat during the plasma-spraying as the particles traverse the plasma plume. As a result of the superheat, the alloy is changed in its composition to reduce the aluminum concentration and to increase the niobium and titanium concentrations on a relative basis.

Abstract: A solid particle erosion resistant coating includes angular titanium carbide particles uniformly dispersed through a high chromium iron matrix. In one form, the aggregate comprises, by weight, about 30-50% TiC, about 10-30% Cr, about 1.5-5% C and the balance essentially iron in the form of ferrite. The matrix also includes metallurgically identifiable amounts of high chromium content M.sub.7 C.sub.3 carbides therethrough. The coating does not exhibit austenitic or martensitic structure therethrough. A powder alloy consolidated body also includes a surface adjacent region having a similar TiC and high chromium iron matrix. Further, a method for obtaining the coating includes heating above the austenitization temperature of the matrix alloy and below the melting temperature of iron, and cooling the aggregate so as to attain iron in the form of ferrite in the matrix.

Abstract: A solid particle erosion resistant coating includes angular titanium carbide particles uniformly dispersed through a high chromium iron matrix. In one form, the aggregate comprises, by weight, about 30-50% TiC, about 10-30% Cr, about 1.5-5% C and the balance essentially iron in the form of ferrite. The matrix also includes metallurgically identifiable amounts of high chromium content M.sub.7 C.sub.3 carbides therethrough. The coating does not exhibit austenitic or martensitic structure therehthough. A powder alloy consolidated body also includes a surface adjacent region having a similar TiC and high chromium iron matrix. Further, a method for obtaining the coating includes heating above the austenitization temperature of the matrix alloy and below the melting temperature of iron, and cooling the aggregate so as to attain iron in the form of ferrite in the matrix.