36results about How to "Improve grain uniformity" patented technology

A crystalline semiconductor film is manufactured by a first step in which a crystalline semiconductor film is formed on and in contact with an insulating film and a second step in which the crystalline semiconductor film is grown in a condition where a generation frequency of nuclei is lower than in the first step. The second step is conducted in a condition where a flow ratio of a semiconductor material gas to a deposition gas is lower than in the first step. Thus, a crystalline semiconductor film whose crystal grains are large and uniform can be obtained and plasma damage to a base film of the crystalline semiconductor film can be reduced compared with a crystalline semiconductor film in a conventional method.

The invention relates to a process for the preparation of fine barium titanate (BaTiO₃) powders. The process comprises introducing an aqueous solution (I) containing salts of barium and titanium, and an aqueous basic solution (II) containing an inorganic or organic base separately and simultaneously into a high-gravity reactor with the high-gravity level of 1.25G to 12,500G and performing the reaction of the solution (I) with the solution (II) at a temperature of from 60 to 100° C. The solution (I) is preheated to a temperature ranging from 60° C. to 65° C. and the solution (II) is preheated to a temperature ranging from 60° C. to 100° C. respectively prior to the reaction, in which the Ba/Ti molar ratio in the solution (I) is more than 1 and the concentration of the base in the solution (II) is such that the reaction mixture is maintained at a constant OH⁻ concentration, preferably a pH value of about 14. The reaction product is separated by filtering and washed with deionized water to remove the impurity ions and excessive barium ions, and then dried to obtain BaTiO₃ powders. Said powders consist essentially of crystalline, primary particles having a uniform particle size ranging from 5 to 200 nm, an approximately spherical morphology and a high sintering activity.

The invention belongs to the technical field of ceramic synthesis and provides a method for preparing a strontium lanthanum manganate/copper calcium titanate composite magnetoelectric ceramic materialby virtue of a sol-gel method. The method comprises the steps of respectively preparing lanthanum strontium manganite (LSMO) precursor powder, copper calcium titanate and CCTO precursor powder by virtue of the sol-gel method, mixing the LSMO precursor powder with the CCTO precursor powder, adding an adhesive, uniformly mixing, pressing to form a ceramic blank, and sintering a ceramic blank, so asto obtain a strontium lanthanum manganate/copper calcium titanate (LSMO-CCTO) composite magnetoelectric ceramic sample. The method has the beneficial effects that the raw materials are low in cost; components in the reaction process are controllable, and an impure phase is avoided; the gelling time is short; a preparation process is simple, and the dielectric property and magnetism of the ceramicsample have very strong regularity; a ceramic wafer is high in density and grain uniformity; and the process is simple and easy for industrial production, the prepared ceramic sample is high in density and grain uniformity and excellent in magnetoelectric performance.

The invention discloses a preparation method for a Zr-doping CaCu3Ti4O12 ceramic material with a high dielectric constant and low dielectric loss by utilization of a sol-gel method, and belongs to the dielectric material synthesis technology field. The concrete method is as follows: a sol-gel method is employed, calcium nitrate, cupric nitrate, zirconium oxynitrate and butyl titanate are employed as raw materials, absolute ethyl alcohol is employed as a solvent, nitric acid is employed to adjust the pH of a solution, the raw materials are weighed according to chemical element mol ratios, sol is prepared and placed in a water-bath kettle, stirring is carried out continuously until xerogel is formed, organic matters are removed, CaCu3Ti4-xZrxO12 precursor powder is obtained, then calcining, crushing, grinding, sieving and granulation are carried out, then a ceramic body with a thickness of 1mm and with a diameter of 12mm is prepared, then the ceramic body is placed in a sintering furnace, sintering and thermal insulation are carried out, and finally a CaCu3Ti4-xZrxO12 ceramic sample can be obtained. The method is simple in technology and is easy for industrial production. The prepared ceramic sample has a high density, good particle uniformity and has an enough high dielectric constant and low dielectric loss.

The invention discloses a fine grains strengthening-toughening process after forging a 1Mn18Cr18N steel shroud ring rolling piece for manufacturing a generating set, comprising the steps of: cold pre-deforming and solution heat treating the rough machined 1Mn18Cr18N steel shroud ring rolling piece, and sampling testing the solution heat treating effect. According to the invention, austenitic steel forging piece which is essentially coarse grains and can not refine grains by heat treatment has fine and uniform grains before cold deformation strengthening, thus to greatly improve the strength, plasticity and toughness of the forging piece, as well as strengthen the quality controllability.

The invention discloses high-strength metal ceramic used for cutting a nonferrous metal sheet and a preparation method thereof. The preparation method includes the following steps that a, original TiC powder, original Mo powder, original Ni powder and NbC powder are taken and ground through a ball milling medium for 48-64 h, and then slurry is obtained, specifically, the average fisher particle size of the original TiC powder is not greater than 1.0 [mu]m, and the mass ratio of the original TiC powder is 44%-46%; the average fisher particle size of the original Mo powder is not greater than 1.0 [mu]m, and the mass ratio of the original Mo powder is 14%-16%; the average fisher particle size of the original Ni powder is not greater than 1.0 [mu]m, and the mass ratio of the original Ni powder is 38%-40%; the average fisher particle size of the NbC powder is not greater than 1.0 [mu]m, and the mass ratio of the NbC powder is 0.8%-1.2%; the ball milling medium comprises hard alloy bar balls and absolute ethyl alcohol, or comprises hard alloy bar balls and No.120 aviation gasoline; b, the slurry obtained through the step a enters a stainless steel container through a stainless steel screen; and c, after the slurry is subjected to standing in the stainless steel container for 24 hours and under the condition that the ball milling medium comprises the hard alloy bar balls and the absolute ethyl alcohol, the absolute ethyl alcohol on the upper layer of the slurry is taken out.

The invention discloses a method for elongating and turning over a mandrel with an upper flat and a lower V anvil. The divergence angle η of the large deformation zone is determined according to the reduction rate ΔH and the V anvil angle θ; there are two strong zones and one weak zone under the flat anvil, and a reasonable overturning process should give full play to the single anvil reduction effect so that the strong and weak zones can be reasonably matched. The deformation of the outer layer of the forging is equivalent to the deformation of the layer near the mandrel, thereby improving the uniformity of the overall deformation of the forging, so the theoretical flip angle ω should be η/2; after rounding the number of flips n, it can be changed from 360°/n Obtain the actual flip angle ω _t ; Considering that the deformation uniformity and compaction effect are poor during sequential turning, n turning should be divided into multiple groups for pressing, and each group is pressed symmetrically along the circumference. The flipping method of the invention can significantly improve the deformation uniformity in the circumferential and radial directions of the circular section of the forging, and improve the compaction effect of the forging.

The invention discloses a forging method achieving the uniformity of crystal particles of a GH141 abnormally-shaped annular forged piece, and belongs to the technical field of forging technologies. According to the technical scheme, the forging method is characterized by comprising the following steps that S1, heating is conducted, specifically, a GH141 alloy bar is heated to enable the temperature to be 1100 DEG C, and heat preservation is conducted after heating is accomplished; S2, upsetting operation and punching operation are conducted, specifically, the GH141 alloy bar is subjected to upsetting operation, and then the GH141 alloy bar is subjected to punching operation, so that a forged blank is obtained; S3, heating is conducted for the second time, specifically, after the forged blank is heated to enable the temperature to be 1080 DEG C, heat preservation is conducted; S4, mandrel supporter hole enlarging operation is conducted, specifically, the forged blank is subjected to mandrel supporter hole enlarging operation; S5, heating is conducted for the third time, specifically, after the forged blank is heated to enable the temperature to be 1080 DEG C, heat preservation is conducted; S6, forging is conducted, specifically, the forged blank is put into a used blank membrane (2), and then a forming punch (1) is utilized to downwards press the forged blank so that the forgedblank can be forged and formed; and S7, cooling operation is conducted, specifically, air cooling operation is conducted. The forging method has the advantage that the degree of the uniformity of thecrystal particles of the GH141 abnormally-shaped annular forged piece is improved.

The present invention provides a Low Temperature Poly-silicon TFT substrate structure and a manufacture method thereof. By providing the amorphous silicon layers in the drive TFT area and the display TFT area with different thicknesses, of which the thickness of the amorphous silicon layer in the drive TFT area is smaller, and the thickness of the amorphous silicon layer in the display TFT area is larger, and thus, in the Excimer Laser Annealing process, different crystallization results are generated with the amorphous silicon layers in the drive TFT area and the display TFT area under the function of the laser with the same energy to achieve the control to the grain diameters of the crystals. The polysilicon layer with larger lattice dimension is formed in the drive TFT area in the crystallization process to raise the electron mobility. The fractured crystals of polysilicon layer in the display TFT area can be obtained in the crystallization process for ensuring the uniformity of the grain boundary and raising the uniformity of the current. Accordingly, the electrical property demands for the different TFTs can be satisfied to raise the light uniformity of the OLED.

The invention relates to the field of aluminum alloy manufacturing, and particularly relates to an aluminum alloy and a preparation method thereof. The preparation method of the aluminum alloy comprises the following steps: (A) injecting first molten aluminum with a pressure of 0.6-0.8 MPa and a temperature of 630-650 DEG C into a cooling model at a temperature of 10-25 DEG C to cool, so that a first semisolid blank is formed; (B) after the first semisolid blank is turned, putting the obtained substance into second molten aluminum at a temperature of 650-680 DEG C to stir, so that second semisolid slurry is obtained; and (C) feeding the second semisolid slurry into an injection chamber, so that a product is obtained. Compared with common die casting methods in the prior art, the preparation method of the aluminum alloy disclosed by the invention can obtain fine grain structures without the addition of a grain refiner, and structures of columnar crystals and oversize dendrites in traditional casting are eliminated, so that products are uniform in grain and better in effect, and the moulding temperature of the products is about 100 DEG C lower than the temperature of common die casting materials.

The invention relates to a manufacture method for a large-size 5N high-purity aluminum target material. When large-size 5N high-purity aluminum is rolled to a certain thickness, in the width direction, temperatures, ranging from T1 to Tn, of rollers are detected every 100 mm to 300 mm, or temperatures of the 5N high-purity aluminum target material are detected every 100 mm to 300 mm in the width direction; and according to the temperature curve chart, a specific working roller cooling curve is set, uniformity of the rolling temperature of the rollers and the 5N high-purity aluminum target material can be ensured in the subsequent rolling pass process, and therefore uniformity, in the width direction, of the large-size 5N high-purity aluminum target material is ensured. The large-size 5N high-purity aluminum target material manufactured through the manufacture method is good in crystal grain uniformity, simple in technological process, short in production period, high in production efficiency and high in finished product rate and has production and market competitive advantages.

A salicide process is provided. A metal layer selected from a group consisting of titanium, cobalt, platinum, palladium and an alloy thereof is formed over a silicon layer. A first thermal process is performed. Next, a second thermal process is performed, wherein the second thermal process includes a first step performed at 600˜700 degrees centigrade for 10˜60 seconds and a second step performed at 750˜850 degrees centigrade for 10˜60 seconds. If the metal layer is selected from a group consisting of nickel and an alloy thereof is formed on a silicon layer, the first step of the second thermal process is performed at 300˜400 degrees centigrade for 10˜60 seconds and the second step of the second thermal process is performed at 450˜550 degrees centigrade for 10˜60 seconds.

The present invention provides a Low Temperature Poly-silicon TFT substrate structure and a manufacture method thereof. By providing the buffer layers in the drive TFT area and the display TFT area with different thicknesses, of which the thickness of the buffer layer in the drive TFT area is larger, and the thickness of the buffer layer in the display TFT area is smaller, different temperature grades are formed in the crystallization process of the polysilicon to achieve the control to the grain diameters of the crystals. The polysilicon layer with larger lattice dimension is formed in the drive TFT area in the crystallization process to raise the electron mobility. The fractured crystals of polysilicon layer in the display TFT area can be obtained in the crystallization process for ensuring the uniformity of the grain boundary and raising the uniformity of the current. Accordingly, the electrical property demands for different TFTs can be satisfied to raise the light uniformity of the OLED.