280results about How to "Avoid microcracks" patented technology

Negative thermal expansion materials, methods of preparation and uses therefor are disclosed. The materials are useful for negative thermal expansion substrates, such as those used for optical fiber gratings.

The invention provides a method for preparing a nanocrystalline metal material containing nano-sized precipitates within a crystal. The method comprises the following steps of firstly, performing high-temperature solution treatment on a coarse crystalline metal material, thereby obtaining single phase solid solution with supersaturated and dissolved alloy element, wherein the coarse crystalline metal material contains alloy element in a matrix, and the solid solubility is reduced as the temperature is reduced; then, performing severe plastic deformation and high-pressure reverse processing at or below the room temperature, thereby obtaining single phase solid solution nanocrystalline material composed of nanocrystalline grains with supersaturated and dissolved alloy element; and finally, ageing the obtained nanocrystalline material at a pressure of 3-25 GPa and at a temperature of 100-800 DEG C, and holding the temperature for 5-8 h, thereby obtaining a nanocrystalline metal material containing nano-sized precipitates within a crystal. The method provided by the invention is wide in suitable material component range, and can be used for effectively avoiding severe plastic deformation to produce microcrack in a material, and the prepared nano-sized precipitates in the nanocrystalline material are distributed uniformly.

The invention discloses a method for machining a forge piece of a large-scale single-flange anti-explosion motor main shaft of an all-fiber texture. The method comprises the specific steps of raw material smelting, heating, first heating number twice upsetting and swaging, second heating number flange and step shaft forging, normalization treatment after forging, workblank detection, nondestructive inspection, mechanical property and metallographic examination, semi-finishing, stabilized heat treatment and the like. According to the method, the all-fiber texture of the forged single-flange anti-explosion motor main shaft is even, the flange root is high in impact-resistant mechanical property, and operation is balanced and free of noise. Meanwhile, the method greatly reduces production cost and is good in economic benefit.

The invention discloses a crystalline silicon solar cell front silver paste and a preparation method thereof. The front silver paste comprises the following components in percentage by weight: 85-90%of silver powder, 5-10% of an organic carrier, 5-10% of an organic carrier, 1.5-5% of composite glass powder, and 0.05-1% of a silver paste additive. The silver powder in different particle size distribution is cooperatively used, the slurry is good in ink permeability, and the silver powder particles in the grid line are more uniformly and tightly filled, so that the sintering density of the gridline is facilitated, the resistance of the grid lines is reduced, and the photoelectric conversion efficiency is improved. The preparation process of the glass powder is simple, the control is facilitated; the glass powder with different components is compounded and used, so that a series of particles are uniform, the softening temperature is low, and the composite glass powder has good wettability to the silver powder and the silicon substrate, a front silver paste prepared from the composite glass powder is sintered on the front surface of the cell, the silver electrode and the silicon havegood ohmic contact and welding performance, and the adhesion strength of the electrode is high.

The invention relates to an air brick for special steel refining, particularly an air brick for special steel refining and a preparation method thereof. The air brick is composed of the following components in percentage by mass: 60-75% of corundum particle and fine powder, 6-11% of activated alumina micropowder, 8-20% of electrofused chrome corundum material, 3-8% of pure calcium aluminate cement, 2-4% of zirconium oxide and 0.1-0.6% of additional water reducing agent. The air brick is suitable for smelting of special steel grades, and has the advantages of excellent high-temperature properties, excellent air permeability, low breaking possibility, favorable high-temperature folding strength and favorable thermal shock resistance. By adopting the curing schedule, the cement in the material can be sufficiently hydrated, thereby enhancing the strength of the semifinished product, and avoiding generating microcracks of possible collisions in the transportation process (the cracks can further extend in the high-temperature calcination process). The firing schedule is adopted to prevent the air brick cracks from generation and enhance the yield of the air bricks.

The invention discloses an electromagnetic field regulation and control method of surface residual stress of an aero-engine component. The regulation and control method comprises the following step: performing electromagnetic field regulation and controlling on the new-made aero-engine component at normal temperature for 3-600s, wherein the electromagnetic field is formed by coupling an alternating magnetic field and a pulsed electric field; the intensity of the alternating magnetic field is 500-30,000A / m; the frequency of the alternating magnetic field is 1-1,000Hz; the maximum peak current of the pulsed electric field is 5-20,000A; the pulse period of the pulsed electric field is 0.01-1.0s. According to the method, the traditional shot blasting process is canceled, and the distribution of residual stress of a surface layer and a near-surface layer of a material of the component is regulated and controlled by an electromagnetic field, so that the manufacturing accuracy and the surface roughness can be improved, the technological process is shortened, the manufacturing cost is lowered, and the manufacturing period is shortened.

The invention relates to an electrode matched with an Mg-Si-Sn-based thermoelectric element and a connecting process thereof. The electrode is a mixture consisting of the following components in percentage by mass, 30 to 50 percent of metal elementary substance Al and the balance of Ni-Al alloy. The electrode and a thermoelectric material interface are well combined, the reliability is high, the technical operation is simple and convenient, and the service life can be prolonged due to the fact that the good thermal match between the electrode and the thermoelectric material reduces the thermal stress at an interface to the greatest degree.

The invention relates to a process of preparing anti-hurricane glass, comprising following steps: cutting and edging glass; heating glass in the tempering furnace to softening point; feeding the glass into cooling room at speed of 25-50 cm / s, the air pressure in cooling room should be controlled at 6.5-7.5 * 103 Pa to make the surface compressive stress reach to more than 150 MPa; putting glass into acid-etching slot for suitable acid etching; washing glass surface with clean water; coating the surface with organic silicon protecting membrane. The invention is characterized by low production cost and short producing time.

The invention discloses a ceramic chip of a NOx sensor. An oxygen pump anode covered with a protective layer on the surface is arranged on a first-layer membrane, an acquisition cavity is formed on the oxygen pump anode and the first-layer membrane, second to fourth through holes are formed in a second-layer membrane, a first diffusion barrier is formed in the second through hole and divides the second through hole into a first measurement chamber and a buffer cavity, a main oxygen pump cathode is arranged in the first measurement chamber, a second diffusion barrier is arranged between the second through hole and a third through hole, the third through hole is a second measurement chamber, an auxiliary pump cathode is arranged in the second measurement chamber, a third diffusion barrier isarranged between the third through hole and the fourth through hole, the fourth through hole is a third measurement chamber, a measurement electrode covered with a protective layer on the surface isarranged in the third measurement chamber, a reference channel is formed in a third-layer membrane, a reference electrode covered with a protective layer on the surface is arranged in the reference channel, a heating electrode wrapped in a heating electrode insulating layer is arranged between the fourth-layer membrane and a fifth-layer membrane, an outer lead of the heating electrode penetrates through the fifth-layer membrane to be located on the lower surface of the fifth-layer membrane, and a stress release hole filled with heating electrode insulating layer slurry is formed in the fifth-layer membrane.

The invention provides a glass clamp, a glass conveying device and a glass fixing method. The glass clamp comprises a non-magnetic conduction frame which is arranged vertically, a plurality of magnets and a magnetic conduction frame corresponding to the non-magnetic conduction frame in shape; the plurality of magnets are uniformly arranged on the non-magnetic conduction frame; and the glass plate is vertically clamped between the non-magnetic conduction frame and the magnetic conduction frame, and shape of the non-magnetic conduction frame and the glass plate are adaptive. The glass clamp can clamp the relatively thin glass plates and is difficult to break.

The invention provides a high-carbon steel wire rod inclusion control method. The method comprises converter treatment, refining, continuous casting, continuous rolling and wire rod rolling. In converter treatment, high-carbon steel is produced and after converter treatment, silicomanganese deoxidation is carried out. A LF refining temperature is in a range of 1550-1640 DEG C, refining time is in a range of 60-80min, sulfur content of a steel liquid at the refining finished point is in a range of 0.016-0.025%, oxygen activity is in a range of (10-30)*10<-6>, steel liquid acid-insoluble aluminum content is in a range of 0.0005-0.0025% and titanium content is less than or equal to 0.0010%. In continuous rolling and wire rod rolling, the steel wire rod diameter is in a range of 5-5.5mm, a spinning temperature is in a range of 880-910 DEG C and after spinning, a steel wire rod is fast cooled to 600-650 DEG C. The high-carbon steel wire rod obtained by the method contains fine oxide impurities. In steel wire rod drawing, the sulfide inclusion outside the oxide inclusion can cooperate with matrix deformation so that micro-cracks at two ends of the oxide impurity are prevented and finished product processing performances are improved.

The invention discloses a gas-liquid parallel tube type grinding wheel double laser trimming device. The gas-liquid parallel tube type grinding wheel double laser trimming device comprises gas-liquidcontrol equipment, a gas-liquid control operating platform, a picosecond laser ablation head, a gas-guide flexible pipe, a grinding machine, focusing lenses, a femtosecond laser ablation head, a femtosecond laser device, a laser device control operating platform, control equipment, a picosecond laser device, a fine water-guide pipe, a superhard grinding-material grinding wheel, a gas column flow,a liquid column flow, laser beams and three-dimensional moving platforms. By means of the gas-liquid parallel tube type grinding wheel double laser trimming device and method, the auxiliary gas-liquidparallel tube type grinding wheel double laser trimming device is provided, the situations that diamond grinding particle chip tolerance space of the grinding wheel is reduced and the height of highlighted binder is not enough caused by plasma particles and phase explosion effect are avoided, and the defects of microcracks, graphite metamorphic layers and the like generated by peripheral heat accumulation during diamond grinding are overcome; and by means of the gas-liquid parallel tube type grinding wheel double laser trimming device and the method, the generation of coulomb explosion can beavoided, the surface grating and micro-cone structure of the grinding wheel are reduced, the utilization efficiency of laser energy is improved, and the grinding wheel trimming efficiency and the trimming surface quality are improved.

The invention relates to a combined laser-electric spark-electrolysis machining method and device for micro holes with countersunk heads. The method comprises the steps: carrying out through hole pre-machining on the micro holes with the countersunk heads on a workpiece through a laser beam, carrying out electric spark machining on the countersunk heads of the micro holes through a tubular copper electrode to achieve needed precision of the shape of the countersunk heads basically, and carrying out electrolytic machining electrolysis machining on the whole micro holes with the countersunk heads through a high-speed jet electrolyte beam coaxial with the electric spark machining electrode to remove recast layers remaining after the former two machining steps. The device comprises a laser generation device, a combined electric spark machining and electrolysis machining device, a machining mode conversion device, a working solution circulation system, a power supply and a control system. According to the method, laser machining and electric spark machining are the main machining modes and supplemented by electrolysis machining, and the high speed, high precision and high quality can be achieved at the same time. By means of the method and device, rapid machining of the micro holes with the various special-shaped countersunk heads can be achieved, and various shortcomings caused by the adoption of a single specific machining mode in the prior art can be overcome.