645 results about "Brittle fracture" patented technology

A rigid and brittle bright metal flake is formed of a central layer of a reflective material supported on both sides by dielectric layers. In a preferred embodiment, the metal layer is aluminum having a thickness of about 100 nm and the dielectrics are either silicon dioxide or magnesium fluoride, each having a thickness of about 100 nm. The result is a very thin three-layered metal flake about 300 nm thick that exhibits a uniaxial compressive strength of about 8 times a corresponding uniaxial tensile strength. As a result, the metal flake is then afforded the benefits of rigidity and brittle fracture during the manufacturing and applicational processes which ultimately provides favorable planar and specular reflectance characteristics in the visible wavelength range.

The invention relates to warm mixed asphalt cement and a preparation method thereof. 100 percent of warm mixed asphalt cement comprises the following components in percentage by weight: 90.0-97.0 percent of asphalt cement, 2.0-8.0- percent of rheological modification agent and 0.5-5.0 percent of macromolecular polymer, wherein the rheological modification agent is formed by combining the following substances: (a) byproducts produced in a petroleum refining process, wherein the weight content of aromatics is 50-80 percent, and the kinematic viscosity at 100 DEG C is 20 mm<2>/s to 70 mm<2>/s; and (b) derivatives produced in petrochemical industry, coal chemical industry and forestry chemical industry; through the warm mixed asphalt cement, the high-temperature rutting resistance, low-temperature tensile strength and resistance to brittle fracture of the asphalt cement are improved while energy conservation and environmental protection are realized; the asphalt cement is mainly applied to construction and maintenance of various grades of highways and municipal roads, and is particularly suitable for cities, parks and tunnels with higher environmental protection requirements.

The invention discloses a plugging flexibilizer, comprising the components in parts by weight: 5-12 parts of polypropylene fiber, 20-30 parts of rubber particles, 1-5 parts of high molecular polyacrylamide, 2-8 parts of toughened nylon, 2-8 parts of asbestos section, 5-12 parts of plant fibers, 4-7 parts of calcium hydroxide, and 0.1-0.4 part of polyanionic cellulose PAC-HV. A preparation method of the plugging flexibilizer comprises the following steps: orderly adding the components in parts by weight to a kneading machine according to a conventional preparation method at constant temperature and constant pressure; evenly mixing and stirring; and crushing into a 0.05-1mm granular product. The plugging flexibilizer has the characteristics of being wide in material source, free of toxicity and pollution, simple and convenient in construction technology, good in rheological property, good in pillar-forming property, strong in tenacity, not easy to fragilely fall off, high in plugging success rate and the like, does not easily generate a rupture and a brittle fracture in the drilling process after plugging, and is widely applied to pressure-loaded plugging engineering of low-pressure fractured formation, large cracks, large caves, subterranean rivers and serious voidage formation in petroleum and geological drilling.

Tubular casting processes, such as dip-coating, may be used to form substrates from polymeric solutions which may be used to fabricate implantable devices such as stents. The polymeric substrates may have multiple layers which retain the inherent properties of their starting materials and which are sufficiently ductile to prevent brittle fracture. Parameters such as the number of times the mandrel is immersed, the duration of time of each immersion within the solution, as well as the delay time between each immersion or the drying or curing time between dips and withdrawal rates of the mandrel from the solution may each be controlled to result in the desired mechanical characteristics. Additional post-processing may also be utilized to further increase strength of the substrate or to alter its shape.

Golf clubs formed from bulk-solidifying amorphous metals (i.e., metallic glasses) having high elastic modulus and fracture toughness, and to methods of forming the same are provided. Among other components, the golf club materials disclosed enable fabrication of flexural membranes or shells used in golf club heads (drivers, fairways, hybrids, irons, wedges and putters) exhibiting enhanced flexural or bending compliance together with the ability to deform plastically and avoid brittle fracture or catastrophic failure when overloaded under bending loads. Further, the high strength of the material and its density, comparable to that of steel, enables the redistribution of mass in the golf club while maintaining a desired overall target mass.

A modular column system and a method of constructing the same are constructed by stacking at least one precast unit between a foundation section and a coping section. The precast unit makes use of an internally confined hollow column unit fabricated in advance, and joint sections between the precast units are firmly formed. Thereby, the modular column system can realize a short construction period and economy because reinforcement bars and forms are not used, as well as high resistance to bending moment and reduction in cross section and self-weight of the precast unit, and thus the modular column system can provide easier and more economical assembly, and prevent brittle fracture of the joint section between the precast units.

The invention discloses a lead-free solder alloy. The lead-free solder alloy contains Bi of greater than or equal to 30% and less than or equal to 60%, In of greater than 2% and less than or equal to 5%, a microalloy element (a modificator), a rare-earth element, an anti-oxidization element, and the balance of Sn and inevitable impurities. The lead-free solder alloy is used for effectively improving the reliability problem of brittle fracture of a welded joint due to that Bi-phase crystalline grains in a traditional Sn-Bi alloy system are large and Bi is segregated at a Cu/Cu3Sn interface in the form of particles in the long-term service process of traditional Sn-Bi series alloys; as a result, the mechanical shock and the anti-dropping performance of the traditional Sn-Bi series alloys can be greatly improved.

The invention discloses a free-machining pinion steel and a production technique thereof. The pinion steel comprises the following components in percentage by weight: 0.14-0.22% of C, 0.20-0.35% of Si, 0.95-1.15% of Mn, 0.95-1.15% of Cr, 0.020-0.060% of Al, at most 0.035% of P, 0.012-0.030% of S, and the balance of Fe and inevitable impurities. The technique comprises the following steps: smelting, continuous casting and rolling. In the invention, the Cr-Mn-Al-S pinion steel is used instead of the original Cr-Mn-Ti pinion steel, Al and S elements are added, and the intracrystalline ferrite is sufficiently utilized to refine the crystalline grains. The invention can stabilize the Jominy hardenability, reduce the pinion deformation after heat treatment, enhance the brittle fracture resistance and crack propagation resistance, and improve the free machining capacity of the pinion in the machining process. The invention is applicable to pinion steel as a substitute of 20CrMnTi.

The invention discloses a production method to draw high-quality high-carbon steel green rod, which includes the following steps: firstly, the high-carbon continuous cast steel is heated, and then goes through the treatment processes of rough rolling, medium rolling and prefinishing rolling so that the cumulative rolling elongation n1 equals 65 to 120 times; secondly, the rolled pieces are prewatercooled; and then the rolled pieces go through the prefinishing rolling process for 4 to 10 times, wherein, the elongation n2 equals to 1. 1 to 1. 3 times each time and the finishing temperature is 920 to 1090 degrees centigrade; and then the rolled pieces are prewatercooled for a second time, wherein, the rolled pieces reach a drawing out temperature of 830 to 900 degrees centigrade and are made into scattered rolls; in the end, the scattered rolls are air-cooled, wherein, the temperature of the scattered rolls at the outlet of the air cooling roll table is 330 to 450 degrees centigrade; the rolls are cooled in the air environment to room temperature to produce high quality high-carbon steel green rods for drawing, which have large numbers of sorbites, small interlamellar spacing and stable mechanical properties and are not apt to brittle fracture in the production process.

A lead-free solder joint is formed between a tin-silver-copper solder alloy (SAC), SACX, or other commonly used Pb-free solder alloys, and a metallization layer of a substrate. Interaction of the SAC with the metallization layer forms an intermetallic compound (IMC) that binds the solder mass to the metallization layer. The IMC region is substantially free of any phosphorous-containing layers or regions.

Tubular casting processes, such as dip-coating, may be used to form substrates from polymeric solutions which may be used to fabricate implantable devices such as stents. The polymeric substrates may have multiple layers which retain the inherent properties of their starting materials and which are sufficiently ductile to prevent brittle fracture. Parameters such as the number of times the mandrel is immersed, the duration of time of each immersion within the solution, as well as the delay time between each immersion or the drying or curing time between dips and withdrawal rates of the mandrel from the solution may each be controlled to result in the desired mechanical characteristics. Additional post-processing may also be utilized to further increase strength of the substrate or to alter its shape.

The invention provides a slice resin grinding wheel and a preparation method thereof and belongs to the field of grinding tools. The slice resin grinding wheel solves the problems that existing slice resin grinding wheels are easily subjected to brittle fracture and damage and are short in service lives and not ideal enough in rigidity and self-sharpening performance. The slice resin grinding wheel comprises a grinding body and a reinforcing piece placed in the grinding body so as to enhance rotation strength of the grinding body. The grinding body comprises, by weight, 30-40 parts of white fused alumina, 65-75 parts of microcrystal fused alumina, 5-20 parts of green silicon carbide, 5-10 parts of resorcin-formalin, 10-20 parts of phenolic resin powder, 8-15 parts of cryolite powder and 10-20 parts of pyrite powder. The invention further provides the preparation method of the slice resin grinding wheel. The slice resin grinding wheel has the advantages of being low in production cost, high in rigidity, good in self-sharpening performance and long in service life.

The invention relates to a cold rolling method capable of preventing edge crack and brittle fracture of silicon steel with Si content more than or equal to 3.5 percent. The cold rolling method comprises the steps of firstly preheating an uncoiled steel plate; spraying emulsion and fully closing the flow of the emulsion on the outlet sides of former 1-4 passes; conducting cold rolling by adopting a one-step cold rolling method; coiling, wherein the tension at the starting stage is enabled to be 60-80 percent smaller than the tension under set coiling speed to conduct tension control; conducting subsequent processes according to conventional steps. The cold rolling method capable of preventing edge crack and brittle fracture of silicon steel with Si content more than or equal to 3.5 percent has the advantages that not only can the silicon content be enabled to be more than 3.5 percent to improve the magnetic performance of the silicon steel plate, but also the steel plate can be free of edge cracks during cold rolling, the brittle fracture and reject rate is decreased to 0.15 percent, the rolling time of a single coil can be shortened by no less than 10 minutes, and compared with the prior art, the yield is improved by 28.64 percent.

The present invention relates, generally, to methods for joining an electronic part finished with nickel and an electronic part finished with electroless nickel, which can prevent a brittle fracture, more particularly, to a method for joining an electronic part finished with nickel and an electronic part finished with electroless nickel with a solder by controlling the composition of the solder to prevent a brittle fracture occurring at the solder joining portion.

A method for joining an electronic part finished with nickel and an electronic part finished with electroless nickel, comprising: (1) reflowing solder to a nickel portion of an electronic part finished with nickel to obtain an electronic part where an intermetallic compound and a solder are formed; (2) obtaining an electronic part finished with an eletroless nickel, of which the nickel portion is connected with the solder; and (3) solder-joining an electronic part finished with nickel obtained in the step (1) and the electronic part finished with electroless nickel obtained in the step (2).

The invention relates to a preparation method for an alumina coat on quartz fibre surfaces, and belongs to the technical field of special functional ceramics. The preparation method comprises the following steps: respectively adding aluminum ion, nitric acid and chelating agent in solvent according to the molar ratio of 1: (0.03-0.28): (0.5-1) till all the materials are hydrolyzed to generate sediments; then, adding peptizator to carry out peptization; carrying out reflux heating and stirring for 8 to 24h at a temperature of between 50 and 100 DEG C to obtain transparent and stable Al2O3 sol; putting quartz fibre into a steeping vat of Al2O3 sol for steeping and then heating up and gradually drying the quartz fibre at a temperature of between room temperature and 80 DEG C; and finally, carrying out heat treatment at a temperature of between 450 and 850 DEG C to obtain the quartz fibre coated with the alumina coat. The preparation method is scientific, reasonable and easy to implement; moreover, the Al2O3 coat coated on the surface of the quartz fibre increases material mechanical property and reduces material brittle fracture.

The invention provides the production of a carbon nanotube reinforced high tenacity Fe-based amorphous alloy thermal spray coating and a method. A mechanical ball-milling method or a spray granulation method is utilized to reconstruct Fe-based amorphous powder and a carbon nanotube to form Fe-based amorphous-carbon nanotube composite powder; a spraying material surface is pretreated; and the thermal spraying process is carried out, a plasma spraying technology is adopted to spray the Fe-based amorphous-carbon nanotube composite powder, so the high strength and tenacity Fe-based amorphous coating is produced. The Fe-based amorphous alloy powder comprises components of C, B, Ni, Si, Mo, Cr, W and Fe; and the granularity is 1-100mum. The carbon nanotube is a multi-wall carbon nanotube which has the purity larger than 95%, the external diameter of 8-70nm and the length of 100nm-20mum. The carbon nanotube and the Fe-based amorphous are well combined in the coating, so the reinforcing effect is obvious; and the coating fracture surface presents an appearance of total brittle fracture and local ductile fracture, both the tenacity and strength of the Fe-based amorphous are improved, so a practicable and feasible method for applying the Fe-based amorphous coating in a project is provided.

Disclosed is a method of joining electronic package parts, comprising the steps of: reflowing lead-free solders containing alloy elements on top of each of the electronic package parts having a surface treated with copper or nickel; and mounting the surface treated electronic parts on the lead-free solders then reflowing the lead-free solders to generate intermetallic compound between the lead-free solders and the surface treated portion of each of the electronic parts.

Alternatively, the method of joining the electronic package parts according to the present invention comprises the steps of: forming a plating layer made of alloy elements on top of each of the electronic parts having a surface treated with copper or nickel and reflowing lead-free solders; and mounting the surface treated electronic parts on the lead-free solders then reflowing the lead-free solders to allow the alloy elements contained in the plating layer to be diffused into the lead-free solders and generate intermetallic compound between the lead-free solders and the surface treated portion of each of the electronic parts.

The present invention can prevent brittle fracture of the electronic package parts by deriving alteration of the intermetallic compounds generated from existing lead-free solders when the electronic package parts of electronic devices are solder joined together, thereby ensuring reliability of the electronic devices.

The present invention relates to the field of nano-composite materials, and specifically relates to a halloysite nanotube / epoxy nanocomposite. The halloysite nanotube is a branched polymine grafted halloysite nanotube; the branched polymine grafted weight halloysite nanotube and epoxy resin are in the weight ratio of 0.2-20:100, preferably 0.5-5:100. The hyperbranched polymine is grafted onto epoxidized HNTs, so that the branched structure has rich amino groups to generate stronger chemical bonds or hydrogen bonds between the halloysite nanotube and an epoxy matrix and to enhance the interface effect. The prepared modified halloysite nanotube can effectively improve the impact resistance of epoxy resin and reduce brittle fracture of epoxy resin, and has broad application prospects in the fields of automotive, electronics, functional materials and aerospace.

Tubular casting processes, such as dip-coating, may be used to form substrates from polymeric solutions which may be used to fabricate implantable devices such as stents. The polymeric substrates may have multiple layers which retain the inherent properties of their starting materials and which are sufficiently ductile to prevent brittle fracture. Parameters such as the number of times the mandrel is immersed, the duration of time of each immersion within the solution, as well as the delay time between each immersion or the drying or curing time between dips and withdrawal rates of the mandrel from the solution may each be controlled to result in the desired mechanical characteristics. Additional post-processing may also be utilized to further increase strength of the substrate or to alter its shape.