Structures and methods of manufacture of microstructures within a structure to selectively adjust a response or responses of resulting structures or portions of structures to shock induced deformation or force loading

Abstract

Structures and methods of manufacturing utilizing direction of force loading or shock induced deformation of structures including microstructures produced in accordance with embodiments of the invention are provided. In one example, a method of manufacturing and structure including providing a metallic plate; forming said plate such that an original longitudinal direction of rolling the plate is perpendicular to a long direction of the plate, thus a force load on the plate would then be distributed over the longitudinal direction.

Claims

1. A method of designing and manufacturing microstructures within a structure comprising: defining a structure assembly comprising a plurality of sections including a first structure; defining a first loading force with a predetermined orientation to a selected location or portion of the structure assembly comprising the first structure; defining or determining a desired shock induced deformation structural result or force loading structural response in the first structure with respect to the structure assembly; determining at least one plurality of first microstructures in said first structure at said selected location or portion of the first structure that produce said shock induced deformation structural result or said force loading structural response after application of said first loading force, said shock induced structural deformation structural result or force loading structural response comprising a direction of material flow within said first structure having said at least one plurality of first microstructures that is produced upon application of said first force loading; wherein said first microstructures are formed having a microstructure orientation that will either increase or decrease resistance to deformation at the selected location or portion caused by application of the first force loading at the predetermined orientation at the selected location or portion of the first structure, wherein said first microstructures comprises an elongated or stretched grain shape and microstructure orientation at the selected location or portion relative to the first force loading, wherein required microstructures at the selected location or portion comprises an elongation or stretching of the first structure's material grains in the selected location or portion of the first structure where the elongation or stretching of the material grain is produced to align with an alteration plane that is defined by a predetermined angle with respect to a vector of the first force loading at said selected location or portion of the structure; and manufacturing said first structure with manufacturing-derived microstructures comprising said first microstructures by pressing or rolling the first structure at said selected location or portion of the first structure to produce the elongation or stretching of the material grain at said predetermined angle, wherein said first structure thereby produced comprises said first microstructures having said grains elongated into narrow bands aligned with the direction of material flow produced in response to the first force loading and the first force loading direction.

2. The method of claim 1, wherein said manufacturing includes a forging step.

3. A method of manufacturing a structure with microstructures having a predetermined material flow in at least one section of the structure in response to subsequent shock or loading force comprising: determining one or more material grain alterations in a structure that creates different microstructures in at least one section of the structure comprising elongation or stretching of polycrystalline or material grain in said structure that create a different material flow than other sections of the structure based on design parameters comprising a first force loading, a first force loading direction produced by said first force loading above a first predetermined force value, and a desired or predetermined direction of said material flow within said structure produced upon application of said first force loading at a first vector associated with said first force loading with respect to the structure; providing a metallic plate to be formed into said structure with said microstructures; and forming said one or more material grain alterations in said at least one section of said metallic plate by pressing or rolling at least one portion of said metallic plate to produce the elongation or stretching of the metallic plate's material grains to produce elongated grains that are elongated into narrow bands aligned with the desired or predetermined direction of material flow of said structure produced in response to the first force loading and the first force loading vector.

4. The method of claim 3, wherein said forming one or more material grain alterations by elongating or stretching of the material grains comprises forming said metallic plate by cold rolling or working the metallic plate such that a longitudinal direction of rolling the plate is perpendicular to a long direction of the plate, thus a load on the plate would then be distributed over the longitudinal direction.

5. The method of claim 3, wherein said metallic plate is formed as a shaped charge liner, wherein manufacturing said structure with manufacturing-derived material grain alterations comprises an altered microstructure affecting the shaped charge's liner collapse and shaped charge jet formation from the liner as it collapses towards a focus point of the jet such that the microstructure comprises grains elongated into narrow bands aligned with the desired direction of material flow to orient the material flow towards the focus point.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The detailed description of the drawings particularly refers to the accompanying figures in which:

(2) FIG. 1 shows an exemplary shaped charge and target;

(3) FIG. 2 shows an exemplary plates, tubes, rods, and thin shapes and descriptions of rolling direction and metal forming;

(4) FIG. 3 shows an exemplary plate with a high angle loading with regarding to a shock;

(5) FIG. 4 shows an exemplary plate with a low angle loading with regard to a shock;

(6) FIG. 5 shows an exemplary plate after a shock has been applied to it with a high angle of deformation;

(7) FIG. 6 shows an exemplary plate after a shock has been applied to it with a low angle of deformation;

(8) FIG. 7 shows exemplary samples cut from a 1100 A1 block to influence microstructures in a resulting exemplary plate;

(9) FIG. 8 shows resulting structures of exemplary plates; and

(10) FIG. 9 shows a simplified diagram of a distributed longitudinally loaded exemplary plate.

DETAILED DESCRIPTION OF THE DRAWINGS

(11) The embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention.

(12) Generally, an effect associated with embodiments of the invention effect can be observed during an experiment designed to investigate strain characteristics of force loads on a structure e.g., explosively loaded thin aluminum, with known variations in microstructure. For example, upon loading with a controlled explosive shock, material with large grains oriented at shallow angles to the direction of an oncoming shock front (resulting in high angles with respect to the shock wave movement) can be observed to distribute the load away from the directly impacted surface area. Conversely, material with small grains oriented with essentially the opposite relative angles; (low angles with respect to the shock front) can be observed to deform dramatically and locally at an impacted area. In one example, shaped charges, factors which impact shaped charge formation can include one or more factors such as grain size, dynamic recrystallization (DRX), particle fracture, and shear bands and slip associated with a liner being subjected to force loading. Embodiments of the invention have potential application into a system that would benefit from an ability to better distribute impact loads.

(13) Referring initially to FIG. 2, a variety of sheet, plate, extruded tube, drawn tube, rolled and extruded rod and thin shapes are shown with direction of rolling as well as aspects of extruded or drawn items such as longitudinal or transverse sections. In one example, metal plates 11 can be constructed with a direction of rolling 3 parallel to a large surface area. An act of rolling the plate can produce this as shown in FIG. 2. An observation was made from an inadvertent construction of a shaped charge liner in such a way that, in conjunction with the complex shock wave development associated with this charge, put a load of a shock wave at a high angle with respect to the direction of rolling of a large grained material.

(14) One such exemplary configuration is showing high angle loading with regard to shock wave is shown in FIG. 3. An exemplary low angle loading with regard to shock is shown in FIG. 4.

(15) Observed deformations associated with different angle deformations are shown in FIG. 5 and FIG. 6. As shown in FIG. 5, a high angle deformation associated with a large grain structure was deformed over a larger area but locally not as severely. FIG. 6 shows a low angle deformation structure that was deformed locally and torn.

(16) Referring to FIG. 7, a cross sectional view of samples cut from 1100 A1 block to influence microstructure in resulting plates. One exemplary embodiment of the invention includes manufacturing a sheet or plate with its microstructure manipulated to orient the microstructure's grains in line with a direction of loading.

(17) A resulting sample from an exemplary method of manufacture is shown in in FIG. 8. A first plate 21 in FIG. 8 can represent a type of plate providing an ability to distribute a vertical load with one orientation of microstructures having a 90 degree orientation to a vertical load. A second plate 23 in FIG. 8 represents a typical plate with a direction of rolling in a long direction and associated with an angle of 0 degrees. A third plate 25 associated with an angle of 45 degrees is also shown.

(18) FIG. 9 shows an exemplary distributed longitudinally loaded plate 31. FIG. 9 depicts one aspect of an embodiment of the invention. The exemplary plate 31 can be constructed in such that an original longitudinal direction of rolling is perpendicular to the long direction of the exemplary plate 31. Thus a load 33 on the exemplary plate 31 would then be distributed over the longitudinal direction. An exemplary embodiment of the invention has advantages such as an ability to distribute impact loads over a larger area without adding mass or size; a potential to reduce mass and size while better distributing load; and wide potential application.

(19) A relative alignment or elongation of a material's microstructure with respect to a flow direction of, e.g., a shaped charge liner, can influence liner collapse kinetics. A presence and orientation of active slip planes in the form of shear bands introduced with manufacturing processes (e.g., cold work) alter the flow stress affecting flow velocity. Shear bands act as dislocation highways and dominant paths for plastic flow. A hypothesis that existing shear bands and corresponding slip planes in the microstructure, aligned at low angles to eventual jet elongation, can thereby enable more efficient flow. Without a pre-aligned structure, energy is lost generating dislocations and grain boundaries that would otherwise be imparted to flow.

(20) During collapse, material that flows along slip planes associated with a direction of hydrodynamic flow that will ultimately occur. When active slip planes are preexisting (pre-aligned), flow is achieved at a higher velocity (sooner), as flow within bands occurs at lower stress (more stably) for a given strain. When active slip systems are not available or aligned with the direction of flow, the load associated with 10s of GPa of pressure results in localized slip in the form of narrow bands of recrystallized grains. These bands form from shear in the direction of motion and also at 45 to this motion as a response to elongation or compression. This appeared as DRX in recovered material. Smaller grains associated with the annealed liner required less energy to recrystallize but did not provide the favorably aligned slip systems.

(21) In some embodiments, aspects can be summarized with the general proposed new relationship between velocity and material properties of equation 1.

(22) $\begin{array}{cc}V:=\left(\frac{\mathrm{hbv}}{2\mathrm{.Math.}}\right)& \mathrm{Equation}1\end{array}$

(23) Equation 1 provides an expression between shaped charge liner kinetics and material properties on some embodiments of the invention. V stands for flow velocity, h represents shear band spacing, represents strain hardening property, p represents mobile dislocation density. Equation 1 can be applied assuming collapse facilitated by sliding along shear bands. The velocity is maximized in a strain-hardened material characterized by a high density of mobile dislocations organized in the direction of flow.

(24) Research associated with this effort has recognized in relation to some embodiments of the invention an association between material prosperities, initial jet velocity and performance. Further, in some examples, this effort has established that a strain-hardened material with a high mobile dislocation density aligned to move in a direction of flow dictated by shaped charge kinetics will result in a higher jet velocity. In other words, liners constructed with heavy cold working in the direction of the liner contour will perform the most successfully. In some embodiments, this implies forging of the liner.

(25) A method of manufacturing can include step 101 comprising determining strain hardened structure design parameters comprising a first force loading, a first force loading direction produced by said first force loading above a first predetermined force value, and a desired direction of material flow of said strain hardened structure produced upon application of said first force loading; at step 103, manufacturing said strain hardened end application structure with manufacturing-derived microstructure affecting shaped charge collapse and jet formation based on said strain hardened structure design parameters, wherein said strain-hardened structure (by forging) comprises a microstructure with grains elongated into narrow bands aligned with the desired direction of material flow.

(26) In some embodiments, effects of shear banding can be induced in the microstructure by the act of forging. The bands enable flow with the liner contour by sliding of grain and sub-grain boundaries. The shear bands can provide highly localized dislocation highways allowing the matrix adjacent to the band to deform plastically at lower stresses. Flow into the collapse point is characterized by these primary shear bands. Once the flow jets along the axis of symmetry, secondary shear bands present in the matrix from strain-hardening elongation align nearly parallel with the direction of flow and thus promote more efficient flow.

(27) Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims.