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Equations of dynamic lathe processes in autocorrelation-function form are considered. The margin of stability of the dynamic system is calculated on the basis of experimental data regarding the selection of the cutting conditions.
Methods of self-programming of the tool trajectory in CNC lathes are considered for the example of turning. By adaptive control, the longitudinal supply is regulated in accordance with the load that acts in cutting.
A design is proposed for the attachment of a replaceable polyhedral insert in the housing of a pass-through lathe cutter with two fixed positions of the insert. This design permits modification of the tool geometry.
The dynamic characteristics of the torsional system in a lathe gearbox are analyzed. The forms of vibration of the torsional system are identified, and the amplitude–frequency characteristics of the gearbox’s dynamic pliability are determined. The resonant peaks at the eigenfrequencies are considered.
Chromium (Cr) alloys combine low density with high-temperature strength but suffer from brittleness and rapid softening. Body-centered orthorhombic (BCO) CrNi 2 laths have been shown to improve Cr-alloy high-temperature strength retention, yet their thermal stability and transformation behavior remain unclear. CrNi 2 conventionally forms through long-range ordering from a face-centered cubic (FCC) phase. Using multiscale microscopy and neutron diffraction, we show that CrNi 2 instead nucleates from a body-centered cubic (BCC) matrix, in a binary Cr 85 Ni 15 alloy. Despite aging above the equilibrium ordering temperature, CrNi 2 persists for ∼220 h at 760 °C before fully disordering, indicating sluggish transformation kinetics. The formation and decomposition follow differing transformation pathways (BCC → CrNi 2 → FCC), revealing kinetic asymmetry not captured by equilibrium Cr-Ni phase diagrams. In conclusion, these findings redefine the transformation behavior of CrNi 2 , establish its metastable kinetic window, and suggest alloying strategies to stabilize CrNi 2 for precipitation strengthening of high-temperature Cr-alloys.
To elucidate changes in the density and substructure of dislocations during tempering of lath martensite steel, a convolutional multiple whole-profile fitting method was applied to in situ neutron diffraction profiles. With increasing tempering temperature, the dislocation density scarcely changed in the beginning and then decreased at temperatures above 473 K, whereas the dislocation arrangement drastically changed at temperatures above 673 K. The strength of the steel is speculated to depend on the density and arrangement of dislocations. - Highlights: • A convolutional multiple whole-profile fitting method was applied. • Dislocation density and dislocation arrangement changing with tempering were discussed. • Dislocation density scarcely changed in the beginning. • And then dislocation density decreased at temperatures above 473 K. • The dislocation arrangement drastically changed at temperatures above 673 K.
This thesis presents the work performed on lathing PBX 9501 to gather and analyze cutting force and temperature data during the machining process. This data will be used to decrease federal-regulation-constrained machining time of the high explosive PBX 9501. The effects of machining parameters depth of cut, surface feet per minute, and inches per revolution on cutting force and cutting interface were evaluated. Cutting tools of tip radius 0.005 -inches and 0.05 -inches were tested to determine what effect the tool shape had on the machining process as well. A consistently repeatable relationship of temperature to changing depth of cut and surface feet per minute is found, while only a weak dependence was found to changing inches per revolution. Results also show the relation of cutting force to depth of cut and inches per revolution, while weak dependence on SFM is found. Conclusions suggest rapid, shallow cuts optimize machining time for a billet of PBX 9501, while minimizing temperature increase and cutting force.
Close-tolerance elliptical cones are fabricated by cutting-tool guide assembly used with conventional tracer cartridge on turret lathe accurately produced in two machine operations.
Self-aligning tool positions and rigidly holds lathe chuck jaws for refacing and truing of the clamping surface. The jaws clamp the fixture in the manner of clamping a workpiece. The fixture can be modified to accommodate four-jawed checks.
Spring loaded device used in conjunction with a standard dial indicator facilitates centering a workpiece in an independent four-jaw lathe chuck.
A lathe tool and holder combination for machining resin impregnated fiberglass cloth laminates is described. The tool holder and tool bit combination is designed to accommodate a conventional carbide-tipped, round shank router bit as the cutting medium, and provides an infinite number of cutting angles in order to produce a true and smooth surface in the fiberglass material workpiece with every pass of the tool bit. The technique utilizes damaged router bits which ordinarily would be discarded.
A computer program calculates the two-dimensional trajectory (radial vs. axial position) of a finite-radius-of-curvature cutting tool on a lathe so as to cut a workpiece to a piecewise-continuous, analytically defined surface of revolution. (In the original intended application, the tool is a diamond cutter, and the workpiece is made of a crystalline material and is to be formed into an optical resonator disk.) The program also calculates an optimum cutting speed as F/L, where F is a material-dependent empirical factor and L is the effective instantaneous length of the cutting edge.
Shock deformed monazite, mono-clinic rare earth element (REE) phosphate, from the Haughton Dome impact structure, Nunavut, Canada, contain lath-structured lamellae. Microstructural phase heritage indicate the former presence of a previously unreported, shock-produced, tetragonal-structured, high pressure polymorph of REEPO4. This study presents an electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) study of shock deformed monazite from the historic sample DIG-9, a shock stage III, biotite sillimanite gneiss sample from near the central uplift of the Haughton Dome (75°22'20"N, 89°40'50"W), in which shock features in monazite were first described.
A lathe leveler for centering a cutting tool in relation to a cylindrical work piece includes a first leveling arm having a first contact point disposed adjacent a distal end of the first leveling arm, a second leveling arm having a second contact point disposed adjacent a distal end of the second leveling arm, a leveling gage, and a leveling plate having a cutting tool receiving surface positioned parallel to a horizontal axis of the leveling gage and on a same plane as a midpoint of the first contact point and the second contact point. The leveling arms and leveling plate are dimensioned and configured such that the cutting tool receiving surface is centered in relation to the work piece when the first and second contact points are in contact with one of the inner surface and outer surface of the cylindrical work piece and the leveling gage is centered.
ThLa crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Th sites. In the first Th site, Th is bonded to six equivalent Th and six La atoms to form ThLa6Th6 cuboctahedra that share corners with twelve ThLa6Th6 cuboctahedra, edges with twelve ThLa6Th6 cuboctahedra, edges with twelve LaLa6Th6 cuboctahedra, faces with six equivalent ThLa6Th6 cuboctahedra, and faces with twelve LaLa6Th6 cuboctahedra. All Th–Th bond lengths are 3.61 Å. All Th–La bond lengths are 3.65 Å. In the second Th site, Th is bonded to ten equivalent Th and six La atoms to form ThLa6Th10 cuboctahedra that share corners with ten LaLa6Th6 cuboctahedra, corners with twelve ThLa6Th6 cuboctahedra, edges with eight LaLa6Th6 cuboctahedra, edges with sixteen ThLa6Th6 cuboctahedra, faces with sixteen equivalent ThLa6Th10 cuboctahedra, and faces with eighteen LaLa6Th6 cuboctahedra. There are a spread of Th–Th bond distances ranging from 3.61–7.23 Å. All Th–La bond lengths are 3.65 Å. There are three inequivalent La sites. In the first La site, La is bonded to six equivalent Th and six equivalent La atoms to form LaLa6Th6 cuboctahedra that share corners with twelve LaLa6Th6 cuboctahedra, edges with twelve equivalent ThLa6Th6 cuboctahedra, edges with twelve LaLa6Th6 cuboctahedra, faces with six equivalent LaLa6Th6 cuboctahedra, and faces with twelve equivalent ThLa6Th6 cuboctahedra. All La–La bond lengths are 3.61 Å. In the second La site, La is bonded to six Th and six equivalent La atoms to form LaLa6Th6 cuboctahedra that share corners with five equivalent ThLa6Th10 cuboctahedra, corners with twelve LaLa6Th6 cuboctahedra, edges with ten ThLa6Th6 cuboctahedra, edges with twelve LaLa6Th6 cuboctahedra, faces with six equivalent LaLa6Th6 cuboctahedra, and faces with fifteen ThLa6Th6 cuboctahedra. All La–Th bond lengths are 3.65 Å. All La–La bond lengths are 3.61 Å. In the third La site, La is bonded to six Th and six equivalent La atoms to form LaLa6Th6 cuboctahedra that share corners with five equivalent ThLa6Th10 cuboctahedra, corners with twelve LaLa6Th6 cuboctahedra, edges with ten ThLa6Th6 cuboctahedra, edges with twelve LaLa6Th6 cuboctahedra, faces with six equivalent LaLa6Th6 cuboctahedra, and faces with fifteen ThLa6Th6 cuboctahedra. All La–La bond lengths are 3.61 Å.
The influence of electromechanical treatment on the hardening of VT22 titanium alloy is determined. The microstructure of the hardened surfaces is investigated, and the hardness is measured at different depths. Recommendations are made regarding the selection of electromechanical treatment methods.
Ferritic/Martensitic (F/M) steels with high Cr content posses the high temperature strength and low swelling rates required for advanced nuclear reactor designs. Radiation induced segregation (RIS) occurs in F/M steels due to solute atoms preferentially coupling to point defect fluxes which migrate to defect sinks, such as grain boundaries (GBs). The RIS response of F/M steels and austenitic steels has been shown to be dependent on the local structure of GBs where low energy structures have suppressed RIS responses. This relationship between local GB structure and RIS has been demonstrated primarily in ion-irradiated specimens. A 9 wt.% Cr model alloy steel was irradiated to 3 dpa using neutrons at the Advanced Test Reactor (ATR) to determine the effect of a neutron radiation environment on the RIS response at different GB structures. This investigation found the relationship between GB structure and RIS is also active for F/M steels irradiated using neutrons. The data generated from the neutron irradiation is also compared to RIS data generated using proton irradiations on the same heat of model alloy.