Surface Finish Profile Research Articles

An Uncut Chip Thickness and Surface Finish Model for Contour Turning with a Corner and Edge Radiused Insert

Uncut chip thickness h and total surface finish profile height Rt is modeled in general contour turning where feed rate is oblique to the workpiece X-axis in the XY plane. The insert surface was parameterized with arc-lengths along corner and edge radius applying a common template. For true insert orientation, projecting the grazing curve GC on the XY plane, h was measured normal to projection at every point. Revolving the GC about X, its subsegment producing surface finish imprint solved and Rt calculated. Contact extremities agreed with published data in cylindrical hard-turning. Brammertz BE and Side-Flow SF effects in surface generated were further modeled. The Rt plateau at low feed rates for BE was smaller for smaller minimum uncut chip thickness (hmin) imposed. A greater side-flow angle (SFA) increased Rt for a fixed feed rate. Tighter bounds to published Rt varying hmin and SFA were rapidly obtained due to use of the common template. Departure from plane strain responsible for SF at cut extremity on the finished surface based on published orthogonal cutting width to h ratios were quantitatively predicted.

The optimization of squeeze casting process parameter for AA2219 alloy by using the Taguchi method

The squeeze casting process have huge potential to produce excellent smooth surface finish profile and have a capability to produce near net product. The squeeze casting is a combination process of forming and forging with a single stage operation without porosity. An attempt is made to optimize the process variables of squeeze casting parameter such squeeze pressure load, die and melt temperature using the L9 orthogonal array with three different levels in order to determine the S/N ratio for density and hardness which is considered as response of the squeeze casting operation. Taguchi analysis performed on the response of squeeze casting in order to determine the most significant process parameter effecting on hardness and density. The Regression equation was devolved to perform a confirmatory test. The Squeeze casting process parameter optimized for AA2219 alloy at squeeze pressure 650 MPa, die pre heating temperature 225°c and melt temperature 700°C which produced better mechanical response and metallography structure. The microstructure of squeeze casted sample was analysed along the radial direction with help of an optical microscope. Microstructure evaluation conforms the presence of fine grains which can be obtained only at the optimized process parameter.

Surface topography and roughness in hole-making by helical milling

Helical milling is used to generate holes with a cutting tool traveling on a helical path into the workpiece in which the diameter of the hole can be adjusted through that of the helical path. Based on an improved Z-map model, a 3D surface topography simulation model is established to simulate the surface finish profile generated after a helical milling operation using a cylindrical end mill. The surface topography simulation model incorporates the effects of the relative motion between the cutting tool and the workpiece, in which the effect of the insert runout error of the cutting tool is considered. Furthermore, the roughness parameters are deduced from simulations of the 3D surface topography. The experimental result shows that the proposed simulation algorithm can predict well the surface roughness in a helical milling operation. The surface topography simulation model is used to study the effects of cutting conditions such as the tangential feedrate, the diameter of the cutting tool and the hole, the insert runout error of the cutting tool, as well as the revolution of the cutting tool around the axis of the hole on the surface finish profile. It is found that the surface quality can be improved by optimization of the cutting conditions. As a result, the proposed model will be helpful in determining the cutting conditions to meet surface finish requirements in helical milling operation.

Modeling of virtual workpiece with machining errors representation in turning

Virtual manufacturing (VM) is one of the research focuses in manufacturing at present. By analyzing and modeling the forming process of workpiece and the error sources contributing to machining precision of workpiece in turning operation, the cutter trajectory and attitude representation (CTA_Rep) is presented to characterize the geometric errors of machined workpiece in VM. Then a surface topography simulation model is established to simulate the surface finish profile generated after a turning operation. This representation is implemented in the Virtual Machining and Measuring Cell (VMMC) developed by the authors to represent and predict the geometric errors of workpiece. Satisfactory results are obtained.

An Improved Time Domain Simulation for Dynamic Milling at Small Radial Immersions

This paper presents an improved milling time domain model to simulate vibratory cutting conditions at very small radial widths of cut. The improved kinematics model allows simulation of very small radial immersions. The model can predict forces, surface finish, and chatter stability, accurately accounting for non-linear effects that are difficult to model analytically. The discretized cutter and workpiece kinematics and dynamic models are used to represent the exact trochoidal motion of the cutter, and to investigate the effects of forced vibrations and changing radial immersion due to deflection and vibrations on chatter stability. Three dimensional surface finish profiles are predicted and are compared to measured results. Stability lobes generated from the time domain simulation are also shown for various cases.

Advanced measuring techniques for the production of ultra-thin hot strip

When producing ultra-thin hot strip, the yield and economy depend on achieving narrow geometrical and material properties fulfilling the increased customers demand. In production, the correct measurement of the strip properties is necessary. This paper gives advanced measuring and control techniques for the parameters concerning thickness profile, flatness profile, coil face profile, temperature profile, surface finish profile of ultra-thin hot rolled strip.

A study on the effects of vibrations on the surface finish using a surface topography simulation model for turning

In this paper, a surface topography simulation model is established to simulate the surface finish profile generated after a turning operation. The surface topography simulation model incorporates the effects of the relative motion between the cutting tool and the workpiece with the effects of tool geometry to simulate the resultant surface geometry. It is experimentally shown that the surface topography simulation model can properly simulate the surface profile generated by turning operations. The surface topography simulation model is used to study the effects of vibrations on the surface finish profile. It is found that the vibration frequency ratio is a more important vibration parameter than the vibration frequency on the characterization of the surface finish profile. The vibration frequency ratio is the ratio between the vibration frequency and the spindle rotational speed.

An evaluation of the influence of cylinder liner finish and synthetic lubricating oil on exhaust hydrocarbon species from an SI engine

AbstractAs part of the continuing attempt to reduce emissions from automotive engines this paper investigates the effect of cylinder lubrication on hydrocarbon emissions, and shows that the effect of a synthetic oil on total emissions is insignificant. However, more positive results have been obtained using cylinder surface finish to control oil layers in the combustion chamber. Studies of the hydrocarbon species in the emissions showed significant differences due to surface finish profiles.

Assessment of Surface Finish Profiles Produced by Multi-Process Manufacture

Many critical parts are made by a multiplicity of processes, some of which are left on the completed part. This paper describes modern methods of measuring them.

Surface Profilometry Based on Fringing Capacitance Measurement

A rugged, compact sensor for in-process measurement of surface finish profiles is proposed. The concept is based on the detection of variations in the fringe electric field generated between the surface and a perpendicular, ceramic-encased electrode. An analysis of both static and spatial dynamic characteristics of this “capacitive profilometer” is presented. For some surfaces, the device acts as a low-pass spatial filter, attenuating the higher spatial frequencies. A method of dynamic compensation, based on Fourier transform techniques, is developed. Experimental results demonstrate the validity of the analysis and dynamic compensation. Direct comparisons of surface profiles measured with the capacitive and standard stylus-type are presented and show good agreement.