5 results about "Shear strain rate" patented technology

The invention relates to the technical field of amorphous alloy preparation and die-casting forming, and provides a die-casting amorphous alloy mechanical property regulation and control method which comprises the steps that S1, selected amorphous alloy raw materials are placed into a smelting crucible; s2, a smelting vacuum environment is constructed; s3, the smelting crucible is heated, so that the amorphous alloy raw materials in the smelting crucible are molten into a molten state; s4, the amorphous alloy melt is poured into a charging barrel; s5, the amorphous alloy melt in the charging barrel is injected into a cavity of the die-casting die; the shear strain rate during mold filling of the amorphous alloy melt is regulated and controlled by adjusting the injection rate; s6, the amorphous alloy melt is subjected to pressure maintaining solidification, and an amorphous alloy structural part is obtained after mold opening; and S7, the amorphous alloy structural part is machined into the standard test size to be subjected to mechanical property detection, and technological parameters meeting the target performance requirement are screened out. By means of the method, the problems that an existing amorphous alloy is single in performance regulation and control means and high in cost can be solved.

The application relates to the field of power module reliability evaluation, and particularly discloses a crystal plasticity constitutive model construction method based on a density characteristic, which comprises the following steps: S1: modifying the initial value and the saturation value of a critical decomposed shear stress through a correction coefficient; S2: taking the initial value and the saturation value of the corrected critical decomposed shear stress obtained in the step S1 as parameters and substituting the parameters into a hardening law of a crystal plasticity constitutive model to establish the crystal plasticity constitutive model based on the density characteristic; and S3: simulating in finite element software based on the crystal plasticity constitutive model established in the step S2, inputting values of different density characteristic parameters and macroscopic shear strain rates, and calculating and outputting the mechanical performance prediction result of the material. The application effectively quantifies the influence of manufacturing process uncertainty on the mechanical performance of a packaging interconnection material by introducing the density characteristic parameter, and improves the accuracy of simulation analysis.

The invention discloses a crystal plasticity constitutive model construction method under an ultrasonic vibration auxiliary processing condition, and relates to the technical field of ultrasonic auxiliary processing, a multi-stage deformation frame is constructed, and a total deformation gradient is decomposed into an elastic deformation gradient, a plastic deformation gradient and a thermal deformation gradient; introducing an ultrasonic softening factor and a thermal softening factor into the classic crystal plastic constitutive model, and correcting a shear strain rate expression; establishing a crystal plasticity constitutive equation considering the ultrasonic vibration and temperature coupling effect; establishing a three-dimensional polycrystalline representative volume element model, and applying an ultrasonic cyclic load and a thermal load in finite element software; and developing a user material subprogram, and integrating the crystal plasticity constitutive equation to a finite element platform for numerical simulation. The method is closer to actual material response, the problem that the ultrasonic thermal coupling effect is difficult to accurately simulate by a crystal plasticity finite element method is solved, and the model prediction precision is improved.

The present disclosure provides: a three-dimensional molded body that contains a liquid crystal polymer, can be molded without any defects in appearance, and has a deep-drawn part; and a method for producing the three-dimensional molded body.　A three-dimensional molded body (1) according to the present disclosure comprises a liquid crystal polymer film containing a thermoplastic liquid crystal polymer, or a film-form or sheet-form laminate including the liquid crystal polymer film, and has a structural part (10) composed of a bottom-surface part (11) and a side-surface part (12) that rises from the peripheral edge of the bottom-surface part. The ratio (H / W) of the maximum height (H) [mm] of the structural part to the maximum outside diameter (W) [mm] of the side-surface part is 1 / 10 to 5 / 10. The thermoplastic liquid crystal polymer has a melt shear viscosity of 3,000 to 90,000 Pa∙s at a temperature of Tm+15°C which is obtained by adding 15°C to the melting point (Tm) of the thermoplastic liquid crystal polymer and a shear strain rate of 0.1 rad / s, and has a melt shear viscosity of 80 to 1,000 Pa∙s at the temperature of Tm+15°C and a shear strain rate of 100 rad / s.

This invention relates to a FOW (Field-Write Object) stacked packaging structure with bonding grooves. This FOW stacked packaging structure modifies the traditional form of the FOW film, obtaining a FOW film with bonding grooves through exposure and development. After the FOW film with bonding grooves is bonded to a second chip, the FOW film with bonding grooves is vertically bonded to a first chip and the bonding wires connecting the first chip to the substrate. The bonding wires connecting the first chip to the substrate are inserted into the bonding grooves of the FOW film. Heating melts and reshapes the bonding grooves, allowing the FOW film to complete the bonding and stacking process between the first and second chips, thus realizing this FOW stacked packaging structure with bonding grooves. In response to the trend of increasingly smaller bonding wire diameters, this design expands the applicability of FOW films, reducing requirements on their flowability, shear stress, and shear strain rate, thus improving their versatility. This FOW stacked packaging structure with bonding wire grooves ensures that the bonding wires connecting the first chip to the substrate are not subjected to the stress applied during chip bonding, significantly reducing defects such as loose connections and wire punching. Furthermore, this FOW stacked packaging structure with bonding wire grooves allows for the selection of more long-shelf-life FOW materials, reducing additional costs incurred due to film expiration and improving the utilization rate of FOW films.