Abstract: The cross section of a beam is flattened by causing a plasma beam (25) extracted by a convergence coil from a plasma gun to pass through the magnetic field that extends to the direction orthogonal to the direction in which the plasma beam travels and is formed by magnets (27) made of permanent magnets which are oppositely arranged in pairs in parallel with each other. A plasma apparatus is provided using a plasma beam with 0.7?Wi/Wt with a half-value of beam intensity with respect to a width Wt of a flattened beam 28 as Wi. At least one magnet is included which is stronger in intensity of a repulsive magnetic field at the center of the beam.

Abstract: A method and apparatus for microplasma spray coating a portion of a turbine vane without masking any portions thereof. The apparatus includes a microplasma gun with an anode, cathode, and an arc generator for generating an electric arc between the anode and cathode. An arc gas emitter injects gas through the electric arc. The electric arc is operable for ionizing the gas to create a plasma gas stream. A powder injector injects powdered material into a plasma stream. A localized area of the turbine vane is coated with the powdered material without having to mask the turbine vane.

Abstract: A thermal spray apparatus is provided for thermal spraying a coating onto a substrate. The apparatus include a heating module for providing a stream of heated gas. The heating module is coupled to a forming module for controlling pressure and velocity characteristics of the stream of heated gas generated by the heating module. The thermal spray apparatus further includes a barrel capable of directing the stream of heated gas from the forming module. A powder injection module may be provided for introducing powder material into the stream of heated gas.

Abstract: The present invention provides a method and apparatus of producing a dense coating with desirable stress conditions similar to coatings produced by a cold spray processes, but with higher process efficiencies and lower gas consumption. The inventive process combines features of a plasma process method of gas heating and a cold spray process to accelerate the gas, incorporating these elements into a single hybrid process.

Abstract: The invention relates to an apparatus for thermal spraying (1) including a spray gun (2) with a burner (3), wherein an operating media (5) can be supplied to the spray gun (2) via a feed line (4), and a base part (6) which is in communication with a supply unit (8) for the operating medium (5) via a supply line (7). A releasable coupling device (9) is provided, with the feed line (4) including an adapter part (10) such that the adapter part (10) can be connected to the base part (6) by means of the releasable coupling device (9).

Abstract: A handheld air plasma spray is designed. Plasma is generated by a magnetized arc torch running at 60 Hz and is in non-equilibrium state; thus, the plasma effluent has relatively low temperature (touchable) and yet contains high energy electrons (>5 eV) capable to dissociate oxygen molecules to atomic oxygen. The emission spectroscopy of the torch indicates that the plasma effluent carries an abundance of atomic oxygen, which can effectively kill all kind microbes. Moreover, the experimental results show that this plasma can rapidly clot blood. This invention is for sterilization and blood coagulation applications.

Abstract: A thermal spraying method and device that includes a device (1,2) which generates a flame and a device (3) which injects a powder into the flame. The flame-generating device (1,2) includes an end piece (1) out of which the flame is directed towards a substrate subjected to spraying. The powder-injection device (3) includes a frame element (6) that is adapted to be attached to the end piece (1) and to project in the flame ejection direction from the end piece (1). The frame element (6) has a plurality of through-holes (9) extending through it and distributed circumferentially about the frame element (6) as well as at least two powder injection ports distributed about the frame element (6).

Abstract: Methods and apparatuses are disclosed for applying a twin wire arc spray composite coating to achieve surface effects on a substrate having predetermined characteristics.

Abstract: A system for coating a substrate includes a heater that heats the substrate. The heater includes a two-dimensional array of a plurality of heat sources which supply heat to the substrate when the substrate is in the presence of the array of heat sources. The heater further includes a controller that controls the operation of each heat source to heat a localized area of the surface of the substrate according to a predetermined temperature profile for the substrate.

Abstract: In a process for plasma treating a surface, a non-equilibrium atmospheric pressure plasma is generated within a dielectric housing having an inlet and an outlet through which a process gas flows from the inlet to the outlet. A tube formed at least partly of dielectric material extends outwardly from the outlet of the housing, whereby the end of the tube forms the plasma outlet. The surface to be treated is positioned adjacent to the plasma outlet so that the surface is in contact with the plasma and is moved relative to the plasma outlet.

Abstract: The present invention provides a radiofrequency plasma apparatus for the production of nanoparticles and method for producing nanoparticles using the apparatus. The apparatus is designed to provide high throughput and makes the continuous production of bulk quantities of high-quality crystalline nanoparticles possible. The electrode assembly of the plasma apparatus includes an outer electrode and a central electrode arranged in a concentric relationship to define an annular flow channel between the electrodes.

Abstract: The present invention provides a modular plasma spray gun including a sleeve, a core, and a water tube connectable to the sleeve. The sleeve has a cylindrical sidewall defining a central opening through a length thereof for receiving the core. The sleeve includes a mounting member for mounting the sleeve and an associated spray gun to a spray gun manipulator. The core receives an anode housing and is removably disposed in the central opening of the sleeve and includes forward and rearward portions defined by a stepped central bore through a length thereof. The forward portion receives an anode housing therein, the rearward portion for carrying coolant to and from the anode housing. The coolant inlet tube, coolant outlet tube, and gas inlet tube are manually detachable from an opening in the plasma spray gun assembly and have manually removable locks to prevent tube detachment.

Abstract: A plasma gun with two gap electrodes on opposite ends of a chamber of ablative material such as an ablative polymer. The gun ejects an ablative plasma at supersonic speed. A divergent nozzle spreads the plasma jet to fill a gap between electrodes of a main arc device, such as an arc crowbar or a high voltage power switch. The plasma triggers the main arc device by lowering the impedance of the main arc gap via the ablative plasma to provide a conductive path between the main electrodes. This provides faster triggering and requires less trigger energy than previous arc triggers. It also provides a more conductive initial main arc than previously possible. The initial properties of the main arc are controllable by the plasma properties, which are in turn controllable by design parameters of the ablative plasma gun.

Abstract: The invention provides an arc spraying torch head including: a pair of spray material guides attached to a head body so as to face forward and guiding a flexible wire-like spray material inserted therein; a main air nozzle attached to the head body, and jetting main air toward a melting area of the spray material; the head body being provided with an auxiliary air nozzle which jets auxiliary air toward the melting area; the direction of jetted auxiliary air by the auxiliary air nozzle is tilted with respect to the direction of jetted main air by the main air nozzle, the auxiliary air being jetted toward the melting area; and a spray direction of the spray material being inclined with respect to the direction of the jetted main air.

Abstract: A process for increasing the surface tension (“wettability”) of a silicone element crosslinked by polyaddition from a liquid composition containing one or more ?,?-dimethylvinylpolydimethylsiloxanes (PDMS), one or more poly(dimethyl)(methylhydrogenosiloxy)-?,?-dimethylhydrogenosiloxanes, and a platinum crosslinking catalyst. The silicone surface is treated with a homogeneous atmospheric plasma using a plasma spraying apparatus having a rotating head with one or more plasma nozzles that are offset relative to the axis of rotation, each one being capable of generating a plasma jet whose axis is parallel to said axis of rotation. The articles to which the invention relate include composites of flexible substrate (e.g. textile)/silicone coating. Application: adhesive bonding of silicone surfaces crosslinked by ?Si—H/?Si-vinyl polyaddition.

Abstract: A device and a method for plasma spraying are disclosed. The device comprises, a cathode, an anode, a plasma channel formed by the anode and intermediate electrodes, and one or more flowable material injectors. The plasma channel has a throttling portion that divides the plasma channel into a high pressure portion near the cathode formed by at least one intermediate electrode and a low pressure portion near the anode. During operation, a plasma generating gas is heated by the arc maintained between the cathode and the anode, forming plasma. When the plasma passes through the throttling portion, its speed increases to a supersonic speed, and at the same time its static pressure drops. Flowable materials are injected in the plasma flow in the low pressure portion. The particles in the flowable materials are heated by the plasma and the resultant heated particles and plasma are output from the outlet of the plasma channel.

Abstract: A plasma spray device is provided. The plasma spray device includes a plasma chamber region for having a plasma formed and a throat region coupled to the plasma chamber region. The throat region has an end surface and an axial bore. The axial bore is formed substantially along a longitudinal axis of the throat region, and has a non-circular cross-sectional shape. The axial bore at the end surface is for ejecting a plasma stream. The axial bore may include a plurality of grooves formed substantially along the longitudinal axis of the throat region. The cross-sectional shape of the axial bore may alternatively be defined by a plurality of overlapping substantially circular lobes. The plasma stream has a flow that is lineated before the plasma stream is ejected from the axial bore. The plasma stream has an overall particle pattern angle of less than about 50° after the plasma stream exits the axial bore.

Abstract: A plasma spray apparatus in the form of a gun is utilized to apply an antifoulant coating to marine vessels. The apparatus includes a plasma generator, an electrophoresis element, a heating element, a shield gas element, a liquid cooling system, a forced air system, and a vacuum system. The plasma generator ionizes gas to create a plasma stream, which is utilized in part to supply energy to the heating element that heats a powder material. The heated powder material is exposed to the electrophoresis element to create a covalently bonded coating material. The coating material is injected into the plasma stream and is applied to a target surface. The shield gas element injects a gas flow to surround and protect the plasma and coating material stream as the stream is in flight to the target surface. The liquid cooling system cools portions of the plasma generator and heating element. The forced air system cools a portion of the target surface as the coating material is being applied.

Abstract: The present invention provides a modular anode support member for a plasma spray gun including an outer sleeve, an inner sleeve, and a coolant tube connectable to the outer sleeve. The outer sleeve having a cylindrical sidewall defining a central opening through a length thereof for receiving the inner sleeve. The outer sleeve including a mounting member for mounting the outer sleeve and an associated spray gun to a spray gun manipulator. The inner sleeve for receiving an anode housing is removably disposed in the central opening of the outer sleeve and includes forward and rearward portions defined by a stepped central bore through a length thereof. The forward portion for receiving an anode housing therein, the rearward portion for carrying coolant to and from the anode housing. Alignment means are provided for fixing the relative position of the inner sleeve and outer sleeve in assembly.

Abstract: A method of forming a composite overlay compound on a substrate includes forming a mixture including at least one component from a first group of component materials including titanium, chrome, tungsten, vanadium, niobium, and molybdenum. The mixture also includes at least one component from a second group of component materials including carbon and boron, and the mixture further includes at least one component from a third group of component materials including silicon, nickel, and manganese. The mixture of selected component materials is then applied to a substrate material to form an overlay compound on the substrate material. The overlay compound is fused to the substrate to form a metallurgical bond between the substrate material and the overlay compound.

Abstract: A customizable ion fusion formation system and method is used to repair a targeted repair region of a workpiece with successive layers of feedstock material. The system includes a moveable positioning platform and a control platform positioned separate and apart from the moveable positioning platform. A positioning arm is mounted to the moveable positioning platform and has a deposition head, including a plasma torch and a feedstock feeder mounted thereto. The deposition head is positioned relative to the targeted repair region by positioning and repositioning the moveable positioning platform, and thus the positioning arm, thereby providing customizable repair.

Abstract: The invention relates to a plasma spraying apparatus (1) including a plasma torch (2) for heating up a spray powder (3) in a heating zone (4) and a metering unit (5) for metering the spray powder (3), the metering unit (5) for conveying the spray powder (3) into an injection unit (6) by means of a conveyor gas (7) under a predetermined pressure being connected with a conveyor gas unit (9) via a conveyor gas line (8). The injection unit (6) has an inlet (61) and an outlet (62) designed as a powder injector (62) so that the spray powder (3) can be supplied from the metering unit (5) to the injector unit (6) through the inlet (61) by means of the conveyor gas (7) via an injector line (10) to the injector unit (6).

Abstract: A system (10) for coating surfaces of a workpiece (12) comprises a biasing system (242) for connection to said workpiece (12) and an anode (76) such as to negatively bias the workpiece relative to the anode and a vacuum source (42, 44) for evacuating an interior of the workpiece (12). A gas supply (224, 226, 228) is employed for introducing a gas containing a treatment material to said workpiece and a control system (244) controls the biasing system (242), the vacuum source (42, 44) and the gas supply (224, 226, 228) so as to establish a hollow cathode effect within the workpiece (12). A pair of coupling heads (16, 18) are supported on articulated arms (22, 24, 26) movable in one or more of three axes and include removable shields (78) to protect the heads (16, 18) and an anode mount (74) for receiving an anode (76). The articulated arms allow the system to accommodate a plurality of different shaped and different sized workpieces while the shields protect the coupling heads during a deposition process.

Abstract: Bucket tip tenons requiring refurbishment are removed from the bucket tips by grinding. Groups of buckets are clamped on a rotatable table in positions adjacent an induction heating coil and a robotic welding arm, respectively. While one group is preheated, the other group of buckets is in a welding location, enabling the welding head on the robotic arm to sequentially apply weld buildup material to the bucket tips. After applying weld buildup material in multiple passes and sequentially to the bucket tips, the buckets are removed, stress-relieved and the weld buildup material machined to provide refurbished tenons. Upon removal of the buckets from the table, the table is rotated to locate the preheated buckets in welding locations and additional buckets are clamped to the table for preheating.

Abstract: A method for producing components for injection moulding comprising a body made of thermally conducting material with expansion coefficient matching that of the insulating layers and provided with a passage for the material to be injected. At least one strip of electrically conducting material with high change of resistance with temperature, forming a heating resistor or inductor is applied on a electrically insulating base layer previously directly applied on the body. At least one final insulating layer with low thermal emissivity is then applied to optimise electrical efficiency. The method utilises thermal spray techniques and can be applied also for production of other heating equipment.

Abstract: A monolithic microplasma source includes a dielectric substrate having an outer surface that is exposed to a time varying electric field. A gap layer is positioned on an inner surface of the dielectric substrate. A shield including a slit is positioned on the gap layer. A relief structure is formed in at least one of the gap layer and the dielectric substrate. The dimensions of the gap layer, the slit in the shield, and the relief structure are chosen so as to prevent a formation of a continuous film across the relief structure. A chamber containing a gas is positioned adjacent to the shield so that the gas is ionized to form a microplasma when an electric field is induced in the chamber by the incident time varying electric field.

Abstract: An ion fusion formation method is used to manufacture a component from successive layers of feedstock material. A plasma stream is created by energizing a flowing gas using an arc electrode, the arc electrode having a variable magnitude current supplied thereto. The plasma stream is directed to a predetermined targeted region, and the feedstock material is introduced into the plasma stream to produce a pool of molten feedstock in the predetermined targeted region, the molten feedstock being produced at a temperature determined in part by parameters of the variable magnitude current. Prior to introducing the feedstock material into the plasma stream, optimal molten feedstock parameters may be determined for producing the layers of feedstock material. Feeding parameters by which the feedstock material will be introduced into the plasma stream are then adjusted in view of the determined optimal molten feedstock parameters.

Abstract: A controllable heat source, such as a laser or flame torch, can be used to pre-heat a portion of the surface of a workpiece, such as a glass optic or semiconductor wafer. Reactive atom plasma (RAP) processing can be used to modify the pre-heated surface portion, as the pre-heated material will more readily chemically combine with the atomic radicals of the precursor in the plasma. A RAP torch, such as an ICP plasma torch, MIP plasma torch, or flame torch, can be used to shape, polish, etch, planarize, deposit, chemically modify and/or redistribute material on the surface of the workpiece. The material modified by the torch can substantially correspond to the pattern or portion of the surface that was pre-heated by the heat source. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

Abstract: Example embodiments relate to a plasma-spraying device for spraying a powdered material, including electrodes, which may form a plasma channel having an inlet end and an outlet end, and a unit for supplying the powdered material to the plasma channel. The powder supply unit may be arranged between a first section of the electrodes located upstream of the powder supply unit and a second section of the electrodes located downstream of the powder supply, as seen in the direction of plasma flow of the plasma channel.

Abstract: An apparatus to treat a workpiece with an ionizing gas plasma at about atmospheric pressure. The apparatus may include an outer electrode with at least one opening that also serves to hold the workpiece. An inner electrode may fit at least partially within the workpiece so as to create a plasma discharge zone between the inner electrode and an inner surface of the workpiece. A gas supply manifold may be included that directs a gas into the plasma discharge zone. A power supply may be used to generate an ionizing gas plasma in the plasma discharge zone. In one embodiment, there is a coating on an inner surface of the workpiece.

Abstract: A method for repairing cracks in a metal part comprising the steps of providing a metal part having a crack, cleaning the crack to remove an oxide layer, depositing a repair alloy via at least one of cathodic arc deposition and low pressure plasma spraying to cover the crack, and heating the part at a temperature and pressure sufficient to close the crack.

Abstract: A system for thermal spray coating of a particulate material onto a substrate includes a spray gun apparatus having dual vortex chambers for the mixing of fuel gas and oxygen. The apparatus provides a jet flame resulting from a compression wave formed by compressed air. Dual venturis control the flow of fluidized coating material particles to provide smooth and controlled delivery of coating material to the spray gun.

Abstract: The invention relates to a surface treatment device comprising: electrodes (24a, 24b) that are used to initiate an electric arc of stabilised plasma (14); a stabilising channel (12) which is disposed in a body (10) in order to confine the electric arc of stabilised plasma; conduits (38, 39) which are disposed in the body and used to introduce a treatment gas Q1, uniformly distributed along the arc, upstream of the arc in a direction that is essentially perpendicular to axis A of said arc in such a way as to form an activated gas curtain (8); means for introducing a complementary treatment gas Q2 downstream of the electric arc; and a support (28) that is used to hold the object or material to be treated in place and to position the object or material surface to be treated in relation to the body (10).

Abstract: A portable, hand-held microplasma spray coating apparatus comprises an anode, a cathode and an arc gas emitter disposed in a housing, and a powder feeding system, a cooling system and a power source connected to the apparatus. The powder feeding system, cooling system and power source are detachably mounted on a mobile platform. The microplasma spray apparatus can be transported to on-site locations in the field to facilitate quick repair work.

Abstract: The apparatus for the thermal spray delivery of a precursor solution comprises a first solution reservoir, a second solution reservoir, singular or multiple atomizing liquid injector(s) disposed in fluid communication with the reservoirs, a flame source configured to direct a spray from the atomizing liquid injector to a substrate, and a thermal control device disposed in thermal communication with the substrate. The method of depositing a precursor solution at a substrate to form a coating comprises maintaining a substrate at a pre-selected temperature, delivering the precursor solution from a reservoir bank, atomizing the precursor solution, injecting the atomized precursor solution into a flame, and directing the flame to the substrate.

Abstract: An electrode wire for use in a thermal spray process. The electrode wire is formed with a first layer of a first material formed as tubular outer layer and a second layer of a second material, different from the first material, formed as a tubular inner layer located inside the tubular outer layer. The tubular inner layer includes in an outer surface which is located in substantially uniform contact at an interface with an inner surface of the tubular outer layer. The interface between the inner and outer layers is defined by a mechanical bond between the materials of the inner and outer layers. In a method of performing a thermal spray process the electrode wire is caused to vaporize and spray on a substrate surface to form a bondcoat on the substrate surface.

Abstract: A component for a substrate processing chamber comprises a structure having a textured coating with surface grains. The component is evaluated by directing a beam of electrons onto the textured coating of the component to cause at least some of the electrons to be backscattered. The backscattered electrons are detected and a signal image is generated. The component is selected when the signal image exhibits surface grains sized from about 0.1 to about 5 micron. In one version, the component is also selected when the grains are substantially flower shaped.

Abstract: A plasma powder welding device in this invention comprises a powder having an identical kind of main component as that of a work piece, a feeder feeding the powder to the work piece, a welding torch generating a plasma between itself and the work piece for focusing the powder fed by the feeder on the work piece and transferring the powder to the work piece, and a power source supplying an electric power to the welding torch, wherein a distance from the welding torch to a focal point to which the powder is focused is set nearly equal to or more than the height of the torch.

Abstract: An improved automatic feedback control scheme enhances plasma spraying of powdered material through reduction of process variability and providing better ability to engineer coating structure. The present inventors discovered that controlling centroid position of the spatial distribution along with other output parameters, such as particle temperature, particle velocity, and molten mass flux rate, vastly increases control over the sprayed coating structure, including vertical and horizontal cracks, voids, and porosity. It also allows improved control over graded layers or compositionally varying layers of material, reduces variations, including variation in coating thickness, and allows increasing deposition rate. Various measurement and system control schemes are provided.

Abstract: A local environmental cell for a welding spray gun includes an annular ring having a top surface and a bottom surface, wherein the annular ring is adapted for attachment to an outer perimeter of the spray gun; and a plurality of fluid passageways radially disposed about the annular ring having a plurality of openings in the bottom surface of the ring in fluid communication with a vacuum source for providing a vacuum thereto. The use of the local environmental cell permits deposition of local bond coats as well as minimizes the number of steps associated with welding repair processes. For example, the use of the local environmental cell permits welding and formation of a low oxide bond coat during the welding process, thereby eliminating the need for placing the substrate subsequent to a welding process in a separate spray cell to deposit the bond coating.

Abstract: A stationary shroud of a gas turbine engine made of a base metal is repaired by removing any damaged material from a flow-path region of the stationary shroud to leave an initially exposed base-metal flow-path surface; and applying a base-metal restoration overlying the initially exposed flow-path surface. The base-metal restoration is applied by furnishing a source of a structural material that is compatible with the base metal, and depositing the source of the structural material overlying the initially exposed base-metal flow-path surface of the stationary shroud by plasma transferred arc welding to form a repaired base-metal flow-path surface. An environmentally resistant rub coating may be applied overlying the base-metal restoration.

Abstract: The invention recites a plasma-arc spray gun comprising a cathode and an anode defining a longitudinal axis. The anode further includes an external surface and an internal chamber, the internal chamber extending from a first end to a second end. At least a portion of the internal chamber is defined by revolving a non-linear curve about the longitudinal axis. The plasma-arc spray gun also includes a gun body supporting the cathode and the anode.

Abstract: Heating head and mask apparatus are provided for producing electrically conductive heated glass panels that may be used to warm objects or insure unobstructed viewing through glass by removing moisture. The heating head and mask apparatus utilizes either a circularly rotating or an inline heating head and mask apparatus, which deposits conductive metal bus bars into electrical contact with electrically conductive-coatings that are-disposed on the glass panels.

Abstract: A one-piece or otherwise unitary annular shim member made from a carbon material or a metallic is used to maintain a space between stacked annular preforms during a manufacturing process, such as densification. The one-piece structure advantageously simplifies the arrangement of the preforms in a process chamber and causes less deformation in the preforms. The carbon composition also provides beneficial thermal effects that improve the densification process. A debonding coating is provided on the carbon annular shim member in order to facilitate separation of the annular preforms from the shim members. The metallic annular shim member does not require a debonding coating.

Abstract: A system and method for synthesizing nanopowder which provides for precursor material ablation from two opposing electrodes that are substantially axially aligned and spaced apart within a gaseous atmosphere, where a plasma is created by a high power pulsed electrical discharge between the electrodes, such pulse being of short duration to inertially confine the plasma, thereby creating a high temperature and high density plasma having high quench and/or reaction rates with the gaseous atmosphere for improved nanopowder synthesis.

Abstract: The present invention involves coatings deposited on a substrate including a layer having a selected resistivity. The resistive layer can serve as a heat source in a variety of applications and can be fabricated using an arc plasma spraying procedure.

Abstract: Methods for applying thermal coatings on substrates using a diffusion alloyed metal powder are provided. The powder comprises pre-alloyed iron base powder particles having molybdenum particles diffusion alloyed to the base powder particles.

Abstract: A rotating structure of a gas turbine engine is provided by furnishing a rotor disk comprising a hub with a plurality of hub slots in a periphery of the hub, each hub slot having a hub slot surface, and furnishing a plurality of rotor blades. Each rotor blade includes an airfoil, and a root at one end of the airfoil, with the root being shaped and sized to be received in one of the hub slots of the rotor disk. A protective coating is deposited by a wire spray process at a location which will be, upon assembly, disposed between the root of each rotor blade and the respective hub slot surface. The protective coating is a protective alloy having, in weight percent, from about 6.0 to about 8.5 percent aluminum, from 0 to about 0.5 percent manganese, from 0 to about 0.2 percent zinc, from 0 to about 0.1 percent silicon, from 0 to about 0.1 percent iron, from 0 to about 0.02 percent lead, remainder copper and impurities.

Abstract: A twin plasma torch assembly includes two plasma torch assemblies supported in a housing. Each of the two plasma torch assemblies has an electrodes. Plasma gas is introduced into a processing zone around the two electrodes. A shroud gas is introduced to surround the plasma. A feed tube is provided to supply feed material to the processor.

Abstract: A stationary shroud of a gas turbine engine made of a base metal is repaired by removing any damaged material from a flow-path region of the stationary shroud to leave an initially exposed base-metal flow-path surface; and applying a base-metal restoration overlying the initially exposed flow-path surface. The base-metal restoration is applied by furnishing a source of a structural material that is compatible with the base metal, and depositing the source of the structural material overlying the initially exposed base-metal flow-path surface of the stationary shroud by plasma transferred arc welding to form a repaired base-metal flow-path surface. An environmentally resistant rub coating may be applied overlying the base-metal restoration.