Emissivity of the One-Plate Lapping Machine Tool

Journal of KONES. Powertrain and Transport

2015

Self Cite

Temperature on the chip-tool interface is important parameters in the analysis and control of turning process. Due to the high shear and friction, energies dissipated during a machining operation the temperature in the primary and secondary shear zones are usually very high; hence, affect the shear deformation and tool wear. In a single point cutting, heat is generated at three different zones i.e. primary shear zone, chip tool interface and the tool-workpiece interface. The primary shear zone temperature affects the mechanical properties of the work piece-chip material and temperatures at tool-chip and tool-work piece interfaces influence tool wear at tool face and flank respectively. Total tool wear rate and crater wear on the rake face are strongly influenced by the temperature at chip-tool interface. Therefore, it is desirable to determine the temperatures of the tool and chip interface to analyse or control the process. To measure the temperature at the tool-chip interface many experimental methods have been developed over the past century. Since at the interface there is a moving contact between the tool and chip in this work, authors propose infrared method for temperature measuring. To assure possibly high accurate of noncontact temperature measurement there is a need to keep in mind several factors, including determining appropriate value of emissivity. In this work, authors present results of experimental determining emissivity value of tool-chip interface. As initial value, emissivity of polished steel was taken.

“…Images that have been made can be presented as thermal, visible, parallel or as a mix of both ( Fig. 5) [10].…”

Section: Methods Of Turning Temperature Measurementsmentioning

confidence: 99%

Section: Determining the Emissivity Of Steelmentioning

confidence: 99%

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Determining the Emissivity at the Tool-Chip Interface During S235jr Steel Turning

Journal of KONES. Powertrain and Transport

2015

Self Cite

“…It is used in a wide range of applications and industries. Typical examples of the processed components are pump parts, transmission equipment, cutting tools, hydraulic and pneumatic, aerospace parts, inspections equipment, stamping and forging [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Dependence between Workpiece Material Hardness and Face Lapping Results of Steel C45

2015

SSP

The high demands required today by manufacturing engineers for machine parts and tools necessitate very precise machining. The finishing processes are an important perspective to be considered today for meeting the goals like parallelism, tolerances, flatness, and smooth surface. These processes are high-precision abrasive processes used to generate surfaces of desired characteristic such as geometry, form, tolerances, surface integrity, and roughness characteristics. A leading importance in this perspective has the lapping process. It leads to a surface with low roughness and high precision. The topographical structure resulting from lapping is very advantageous in sliding joints, because of the high ability of lubricant retention, as well as in nonsliding joints because of the high load-carrying ability. Many materials can be lapped, including glass, ceramic, plastic, metals and their alloys, sintered materials, satellite, ferrite, copper, cast iron, steel, etc.This paper reports the observations of steel C45 elements lapping process results. Workpieces were rollers with diameter 17 mm and height 10 mm placed in the conditioning rings with use of workholdings. Samples were divided to three groups according to their Vicker’s hardness: 160, 440, and 650 HV. After grinding, lapping process was conducted. Experiments were carried out with an angular speed of the lapping plate set at 65 RPM, and lapping velocity was v = 49 m/min. The lapping pressure was provided by dead weights and during experiments executing p = 0.04 MPa. Samples were lapped during 10, 15 and 20 minutes. Abrasive slurry was composed of silicon carbide grains mixed with kerosene and machine oil. Abrasive grains size was F400/17.The material removal rate (MRR) and specimens surface characteristic are studied in the light of workpiece material hardness. Test results show that applied process parameters are the best for steel which hardness is 440 HV. In that case, the lowest values of Raparameter were obtained in conjunction with satisfactory values of material removal rate. It can be also seen, as could be predicted, that lapping time influenced on lapping results. MRR increases and surface roughness decreases with time. The worst lapping results were obtained for normalized steel (160HV). It can be the effect of surface damage, like scratching and grooving by harder abrasive grains.

“…Its goal is to achieve extremely high flatness of the workpiece and/or close parallelism of double-lapped faces. The other applications include removal of damaged surface and sub-surface layers and, enhancement of the surface finish on workpieces [2,3,4,5].…”

Section: Introductionmentioning

confidence: 99%

The Influence of Workpiece Hardness on Plate Temperature during One Side Lapping

Barylski

2013

SSP

Lapping leads to a surface with low roughness and high precision. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. The goal was to determine the correlation between the basic lapping conditions and wheel temperature. In work [1] authors developed model to estimate the maximum and average temperature rise of the work surface in lapping. According those models temperature rise depends also on workpiece and plate hardness. Because the second is constant during process, this part of research refer only to the influence of workpieces hardness. They were conducted during lapping the samples made of steel 45. To vary the hardness, samples were divide into three groups each with different Knoop hardness value: 175, 471 and 687. The different hardness values were a result of different heat treatment methods used. Every group after grinding were lapped with the same lapping conditions. In the next step the statistical analysis was conducted. It was verified if the plate temperature is influenced by the workpieces hardness. A hypotheses testing method was use. Results were calculated for temperature rise values measured after 300 minutes of machine working. According to them the influence of workpiece hardness on plate temperature is statistically insignificant.