4185 results about "Residual stress" patented technology

A condenser microphone includes a support, a plate having a fixed electrode bridged across the supports, a diaphragm, which has a moving electrode at a center portion thereof and which vibrates due to sound waves applied thereto, and a spacer, in which a first end is fixed to the plate, and a second end is fixed to the near-end portion of the diaphragm so as to surround the center portion of the diaphragm, wherein an air gap is formed between the plate and the diaphragm. This reduces the tensile stress of the diaphragm so as to increase the amplitude of vibration of the diaphragm. Hence, it is possible to increase the sensitivity of the condenser microphone. A structure constituted of the plate, the diaphragm, and the spacer is bridged across the support by means of the bridges, which absorb the residual stress of the diaphragm due to the deformation thereof.

Integral fiber optic-based condition sensors detect conditions of a composite structure, e.g., a coated wire assembly so as to detect damage or conditions that may damage the same. Preferably, at least one optical fiber sensor having a plurality of Bragg gratings written into the fiber at spaced-apart locations along its axial length is integrated into the electrical insulator coating of a wire, wire bundle or wiring harness. The fiber optic sensor may thus be employed to measure the environmental loads on the electrical wiring including stresses from bending, axial loading, pinch points, high temperature excursions and chemical damage. The system is capable of detecting and locating transient conditions that might cause damage to a wiring system or permanent changes in state associated with damage events. The residual stress in the electrical insulator coating of a wire, wire bundle, or wiring harness are used to monitor the evolution of damage by wear or chaffing processes. Detected stress relief on one or more Bragg gratings will thus be indicative of damage to the insulator coating on the conductor. As such, the magnitude of such stress relief may be detected and used as an alert that the wire insulation is damaged to an unsafe extent.

A method of increasing the compressive stress or of reducing the tensile residual stress of a CVD layer, a PCVD layer or PVD layer and a cutting insert for machining.

The invention relates to a method of increasing the compressive residual stress or of reducing the tensile residual stress of a hard material outer layer or a hard material outermost layer in which the coated substrate after coating is subjected to a dry blast treatment using a granular blast agent that, according to the invention, has a maximum diameter of 150 μm.

Multiple criteria are monitored and controlled to enhance the success of direct-metal deposition, including greater control over factors such as deposit layer height/thickness, sub-harmonic vibration, contour path shape, powder mass flow, and deposition speed, and stress accumulation. Sensors are used to monitor some or all of the following parameters during the deposition process: deposit height, width, temperature, and residual stress. A predetermined limit with respect to the yield strength of the material is preferably set. If the stress exceeds that limit sensors will automatically introduce one or more remedial measures, the priority of which is established using a look-up table generated in accordance with prior experimental knowledge. To control temperature induced distortion and stress, an infrared temperature detector may be used in conjunction with a controller to reduce temperature, increase speed and decreased power for purpose of stress management.

The present invention provides a joining structure capable of greatly improving the proof stress and the fatigue property by alleviating the stress concentration and residual stress caused by welding heat at one or both ends of a tabular member.

In the present invention, one or both ends 4 of a tabular member 3 such as a reinforcing rib, fixed to the surface of a structural member 1 in the direction of the principal stress of the structural member 1 so as to protrude in the shape of T, is/are bent in a direction deviating from the direction of the principal stress and, by this, the rigidity at the end(s) 4 of the tabular member 3 decreases and the stress concentration is alleviated. It is preferable to bend one or both ends of a tabular member 3 in the shape of an gradual curve and to the extent that each bent end is formed at a right angle to the direction of the principal stress. The tabular member may have the shape of a flat plate, or it may be bent so that it has the shape of U or V as a whole. Further, the tabular member may be welded to a structural member or formed as an integral part of a structural member.

This invention relates to a method and an apparatus for performing the method of inducing compressive residual stress along the surface of a part. In the preferred embodiment of the invention, the method includes burnishing or deep rolling a surface using a first and a second roller or ball burnishing members, whereby the first and second burnishing members may have a different diameter and/or modulus of elasticity. In another preferred embodiment of the invention, the burnishing operations may be performed while the surface of the part is at different temperatures.

The invention relates to a device for strengthening a laser cladding layer by ultrasonic impact and a method thereof. A conventional powder feeding type laser cladding method is used for preparing the laser cladding layer on the surface of a cladding base material; after one path of laser cladding is finished, the ultrasonic impact is used for playing effects on the laser cladding layer; when a plurality of paths and layers of laser cladding are carried out, the laser cladding and the ultrasonic impact are alternatively carried out. According to the device and the method disclosed by the invention, the laser cladding layer is obviously strengthened to refine tissues of the laser cladding layer and eliminate residual stress in the laser cladding layer; when the ultrasonic impact is used for playing the effect on the laser cladding layer, a plastic deformation layer with a certain depth is formed in the laser cladding layer; grains and crystal lattices in the plastic deformation layer are distorted to form high-density dislocation so that dendritic crystals in condensation tissues of the laser cladding layer are crushed and are dispersed into the laser cladding layer to form small crystal nucleuses which are uniformly distributed and refine the grains; meanwhile, the ultrasonic impact is used for planting pressing stress into the laser cladding layer to counteract pulling stress in the laser cladding layer and eliminate the residual stress in the laser cladding layer.

The invention discloses flexible composite middle layer brazing alloy and a method of utilizing brazing ceramic and metal, and relates to the composite brazing alloy and the method of utilizing the brazing ceramic and metal. The flexible composite middle layer brazing alloy and the method aim at solving the problems that the conventional method is high in cost and the forming of brittle compound of a joint can not be restrained. The flexible composite middle layer brazing alloy is prepared from upper layer brazing alloy, a flexible middle layer and lower layer brazing alloy. The brazing method comprises the steps of: cleaning greasy dirt and impurity on a pre-welding surface; processing the upper-layer brazing alloy, the flexible middle layer and the lower-layer brazing alloy into small sheets; and ultrasonically cleaning and airing ceramic to be welded, metal to be welded, the upper layer brazing alloy, the flexible middle layer and the lower layer brazing alloy by acetone, assembling a workpiece to be welded, and putting the workpiece to be welded into a vacuum heating furnace to braze. According to the method disclosed by the invention, the operation is simple; the residual stress of the joint is released by adding the flexible middle layer; and the forming of the brittle compound of the joint is restrained, and the shearing strength of the joint is improved by 30-109%. The method disclosed by the invention is used for brazing the ceramic and the metal.

Multi-layered, planar microshells having low stress for encapsulation of devices such as MEMS and microelectronics. The microshells may include a perforated pre-sealing layer, below which a sacrificial layer is accessed, and a sealing layer to close the perforation in the pre-sealing layer after the sacrificial material is removed. The sealing layer may further include a nonhermetic layer to physically occlude the perforation and a hermetic layer over the nonhermetic occluding layer to seal the perforation. The various layers may be formed employing processes having opposing stresses to tune the residual stress of the multi-layered microshell. In an embodiment, the hermetic layer is a metal which is deposited with a process tuned to impart a tensile stress to lower the residual stress in the microshell below the magnitude of cumulative stress present in sealing layer and pre-sealing layer.

A bushing (52) has two bushing parts (52, 58), each of which includes a tubular section (54, 60) and a radial flange section (56, 62) Tubular section (54) is inserted into an opening (38) in a work member (40), from one side of the work member (40). Tubular section (60) is inserted into tubular section (54) from the opposite side (44) of the work member (40). A mandrel (M) is moved through the interior of the tubular portion of the bushing to radially and circumferentially expand the tubular portion of the bushing and move the flange sections against the opposite sidewalls of the work member (40). The tubular portions (54, 60) of the bushing (52) is radially and circumferentially expanded an amount sufficient to introduce fatigue life enhancing compressive residual stresses in the work member (40) immediately around the opening (38) in the work member (40).

Methods of separating a strengthened glass substrate having a compressive surface layer and an inner tension layer include translating a laser beam on a surface of the strengthened glass substrate along a line of desired separation from a first edge of the strengthened glass substrate toward a second edge of the strengthened glass substrate. Methods further include backward-propagating a controlled full-body crack within the strengthened glass substrate from the second edge toward the first edge substantially along the line of desired separation. A scribe line may be formed on a surface of the strengthened glass substrate such that the strengthened glass substrate self-separates along the scribe line. A residual stress field may be created within the strengthened glass substrate such that a full-body crack backward-propagates from an exit defect located at the second edge toward the first edge along a line of desired separation, thereby separating the strengthened glass substrate.

A wafer level package structure with a plurality of compact sensors such as acceleration sensors and gyro sensors is provided. This package structure is composed of a semiconductor wafer with plural sensor units, and a pair of package wafers bonded to both surfaces of the semiconductor wafer. Each of the sensor units has a frame having an opening, a movable portion held in the opening to be movable relative to the frame, and a detecting portion for outputting an electric signal according to a positional displacement of the movable portion. Since the semiconductor wafer is bonded to each of the package wafers by a solid-phase direct bonding without diffusion between a surface-activated region formed on the frame and a surface-activated region formed on the package wafer, it is possible to prevent that variations in sensor characteristics occur due to residual stress at the bonding interface.

By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 μm, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.

This invention provides methods of treatment for work products of materials such as steel, bronze, plastic, etc. and particularly welded steel bodies by pulse impact energy, preferably ultrasonic, to relax fatigue and aging and extend expectant life. The treatment may occur (a) at original production, (b) during the active life period for maintenance or (c) after failure in a repair stage. The ultrasonic treatment improves the work product strength. In welded products residual stress patterns near the weld sites are relaxed and micro-stress defects such as voids and unusual grain boundaries are reduced. The basic method steps are non-destructive in nature, inducing interior pulse compression waves with ultrasonic transducers and accessory tools impacting an external product surface with enough impulse energy to heat and temporarily plasticize the metal interior and relax stresses. The nature of the work product interior structure being treated is determined by sensing the mechanical movement at the impact surface of the work body to produce feedback frequency and phase signals responsive to input impact signals. These signals automatically conform driving pulse energy frequency and phase to the input transducers to match the mechanical resonance frequency of the working transducers and increase efficiency of energy transfer. Such feedback signals also are available for automated procedures which can improve product quality and consistency.

A gate insulating film (13) and a gate electrode (14) of non-single crystalline silicon for forming an nMOS transistor are provided on a silicon substrate (10). Using the gate electrode (14) as a mask, n-type dopants having a relatively large mass number (70 or more) such as As ions or Sb ions are implanted, to form a source/drain region of the nMOS transistor, whereby the gate electrode (14) is amorphized. Subsequently, a silicon oxide film (40) is provided to cover the gate electrode (14), at a temperature which is less than the one at which recrystallization of the gate electrode (14) occurs. Thereafter, thermal processing is performed at a temperature of about 1000° C., whereby high compressive residual stress is exerted on the gate electrode (14), and high tensile stress is applied to a channel region under the gate electrode (14). As a result, carrier mobility of the nMOS transistor is enhanced.

A system for quantifying surface characteristics detects and quantifies characteristics of a surface of an object. For example, the system may quantify changes in surface roughness without contacting the specimen and without requiring precise temporal or spatial stability. The system may also quantify the evolution or progression of a particular characteristic of a surface, such as a defect, a slipband, a crack, a microcrack, a pit, a damage feature, corrosion, a contour change, an impact crater, a change in residual stress, and so on. The system may include an energy source, a detector section, and a process section. The energy source transmits a source signal to the surface of the object. The source signal is specularly reflected and/or scattered by the surface to yield one or more received signals. The detector section receives the received signal and, in turn, provides a detector signal indicative of the received signal. The processor applies an algorithm to the detector signal to quantify an evolution in one or more characteristics of the surface.

In one aspect of the present invention, a method for forming a bonded assembly comprises providing a first and second portion of the assembly; preparing a mating surface on each portion that conforms substantially to the mating surface of the other portion; rapidly heating a bonding material while substantially heating no more than a thin surface zone adjacent each mating surface, and rapidly assembling the two portions in such a manner as to confine a fraction of the bonding material between the mating surfaces. The first portion may comprise polycrystalline diamond or thermally stable polycrystalline diamond; the second portion may comprise cobalt-cemented tungsten carbide. The assembly may comprise a tool for high-impact applications.