Conventional Honing Research Articles

Experimental investigation on surface quality in ultrasonic-assisted honing of 304 stainless steel

Honing is a surface finishing technology, which plays an important role in improving the surface quality and working performance of workpieces. However, with the extensive application of hard-to-machine materials and the increasing requirement for the surface properties of workpieces, the performance of conventional honing (CH) is becoming more and more difficult to meet the production needs. The ultrasonic vibration provides a way to overcome the technological constraints of CH and improve the machined surface properties. To realise the ultrasonic vibration of honing stone, a slotted block horn was used as a vibration transmission component and a supporting component of honing stone in this study. Finite element method was used to analyse and optimise the block horn to improve the uniformity of the amplitude on the output surface, to provide stable and efficient vibration for the honing stone. In this study, the effects of processing parameters on surface roughness in CH and ultrasonic-assisted honing (UAH) of stainless steel SUS304 were studied. The results indicated that the application of ultrasonic vibration in honing made a significant contribution to the formation of a dense punctiform morphology and reduction of the defects of the workpiece surface. Moreover, interactions between ultrasonic vibration, speed of revolution, and honing time in UAH make the changes of surface roughness much different from the CH. On the whole, for UAH, it is a feasible approach to improve the surface roughness by using a smaller amplitude, increasing the speed of revolution appropriately, and extending honing time.

Characterization of Lubricated Friction Behavior of Thermal Spray Steel Coatings in Comparison with Grey Cast Iron

This work examines friction properties of smooth-honed thermal spray (TS) low carbon steel coatings produced on an Al-9.0% Si alloy using a plasma transferred wire arc (PTWA) method and an AISI 1010 wire used as feedstock in comparison with the ASM type D grey cast iron (CI) samples subjected to the same (smooth) honing process. CI samples prepared using a standard honing process were also tested for comparison. Reciprocating sliding tests were performed using a Cameron–Plint tribometer against CrN-coated counterfaces within a speed range of 0.06–1.20 m/s covering the boundary and mixed lubrication conditions. Stribeck curves were constructed to show the coefficient of friction (COF) variations with the ratio (λ) of lubricant film thickness to composite surface roughness of TS and CI samples at the mid-stroke position where sliding speeds and surface roughnesses were measured. Examination of the Stribeck curves showed that the TS coated surfaces provided lower COF values compared to CI surfaces given the same smooth honing treatment, e.g., for λ = 2.7 a COF of 0.029 was observed for TS and 0.035 for CI, whereas conventional honing of CI provided a COF of 0.047 under the same condition. Metallographic evidence was given for the surface features and formation of tribolayers on the contact surfaces. The arithmetic mean heights of the surfaces, Sa measured after the tests remained similar for the smooth-honed TS and CI samples. The low COF values of the TS samples were discussed in terms of the surface pores generated during their manufacturing process, and the high oil retention depth ratio (Svk/Sk) of the TS coated surfaces due to the presence of these pores.

Effect of grain size and number of strokes on Rk parameters and emptiness coefficient in honing process

This paper deals with evaluation of the effect of grain size of abrasive particles and number of tool strokes on the roughness values (Rk, Rpk, Rvk, Mr1, Mr2, and Rp/Rt ratio) in flexible honing. The grain size factor was investigated on two levels (400 and 800 mesh) and the number of tool strokes on three levels (1, 3, and 5) based on a full factorial design 2 × 3. Flexible honing was performed after conventional honing, on 30 crankcase cylinders of hermetic compressors made in gray cast iron. The analysis of variance technique showed that the effect of abrasive grain size on the roughness was more significant than that produced by the number of tool strokes. The abrasive grain size caused statistically significant effects on Rpk, Rk, Mr2, and Rp/Rt, whereas the number of tool strokes affected Rpk only. The interaction between these factors affected Rk. The flexible honing process using 800 mesh tool grain size and five tool strokes allowed for the obtainment of surfaces similar to those that resulted from the plateau honing operation. This result can increase the field of application of this process. Flexible honing was not able to remove the waviness present on the crankcase cylinder surfaces, whose amplitude was similar to those presented by the roughness.

Assessment of the effect of cutting parameters on roughness in flexible honed cylinders

This study aims to investigate the effect of the three cutting parameters (rotation, feed rate, and number of tool strokes) on the values of roughness (Rk, Rpk, Rvk, Mr1, Mr2, Rp/Rt ratio, and Vo) in flexible honed crankcase cylinder of hermetic compressors. The study was based on a full factorial design 2 × 2 × 3, where the rotation and the feed rate were investigated in two levels and the number of tool strokes in three levels. The cylinders were initially honed using a multi-spindle honing machine, Gehring model. A set of three honing tools was used each with two strokes, the first for roughing (120 mesh), the second for semi-finishing (270 mesh), and the third for finishing (600 mesh). For conventional honing (CH), the depth of the cut and the feed rate were kept constant. The flexible honing process was carried out after conventional honing (C+FH) in a CNC milling machine using a Silicon Carbide flex hone tool 800 mesh and 24.2 mm nominal diameter considering 12 different cutting conditions. An electromechanical surface roughness tester was used to carry out roughness measurements. The measurement uncertainty was assessed following the recommendations of the GUM-JCGM 101. The analysis of variance (ANOVA) technique was applied, and it was observed that the number of the tool strokes was the factor that contributed the most to the improvement of the surface finish of the cylinders.

Effect of ultrasound on dynamics characteristic of the cavitation bubble in grinding fluids during honing process

The effect of ultrasound on generating and controlling the cavitation bubble of the grinding fluid during ultrasonic vibration honing was investigated. The grinding fluid on the surface of the honing stone was measured by utilizing the digital microscope VHX-600ESO. Based on analyzing the cavitation mechanism of the grinding fluid, the bubble dynamics model under conventional honing (CH) and ultrasonic vibration honing (UVH) was established respectively. Difference of dynamic behaviors of the bubble between the cases in UVH and CH was compared respectively, and the effects of acoustic amplitude and ultrasonic frequency on the bubble dynamics were simulated numerically using the Runge-Kutta fourth order method with variable step size adaptive control. Finally, the cavitation intensity of grinding fluids under ultrasound was measured quantitatively using acoustimeter. The results showed that the grinding fluid subjected to ultrasound can generate many bubbles and further forms numerous groups of araneose cavitation bubbles on the surface of the honing stone. The oscillation of the bubble under UVH is more intense than the case under CH, and the maximum velocity of the bubble wall under UVH is higher two magnitudes than the case under CH. For lower acoustic amplitude, the dynamic behaviors of the bubble under UVH are similar to that case under CH. As increasing acoustic amplitude, the cavitation intensity of the bubble is growing increased. Honing pressure has an inhabitation effect on cavitation effect of the grinding fluid. The perfect performance of cavitation of the grinding fluid can be obtained when the device of UVH is in the resonance. However, the cavitation intensity of the grinding fluid can be growing weakened with increasing ultrasonic frequency, when the device of UVH is in the off-resonance. The experimental results agree with the theoretical and numerical analysis, which provides a method for exploring applications of the cavitation effect in ultrasonic assisted machining.

The roughness characterization in cylinders obtained by conventional and flexible honing processes

Crankcase cylinders of hermetic compressors are produced in large numbers for refrigerators of domestic use. They are, usually, machined by using a three-stage honing process (roughing, semi-finishing, and finishing), and for their characterization during the quality control, an evaluation of roughness is carried out. Although the roughness represents a peerless factor to characterize the honed surfaces, its implementation is a challenge for scientists and technicians in general due to the difficulty of detecting the difference between the surface finish on different honing stages. This paper assesses the roughness of parts obtained by flexible honing applied after conventional honing process by using a portable surface roughness tester and an interferometer in white light mode (chromatic length aberration—CLA). An extensive evaluation of roughness was made using several roughness parameters, graphics, and curves that include the following: roughness profile, topographies, amplitude parameters, Rk family parameters, volume, and feature parameters. The measurement uncertainty associated with all roughness parameters was estimated by applying the methods proposed in the JCGM 101. The results obtained after flexible honing were compared with those found in parts machined by conventional honing. This experimentation showed that flexible honing process when applied after the conventional honing provided an essential improvement of the surface finish and an increase of the repeatability and the quality of honed parts. The volume and the feature parameters can be used as alternative to appropriately characterizing honed surfaces, because they were able of detecting the changes caused on the surface by different stage of honing process.

PRECISION FINISHING OF GEARS BY ELECTROCHEMICAL HONING PROCESS: A STATE OF ART REVIEW

This paper presents a state-of-the-art review of high precision finishing of gears by electrochemical honing (ECH) process. It is an electrochemical (EC)-based hybrid machining process combining the faster material removal capability of electrochemical machining (ECM) process and controlled functional surface–generating capability of conventional honing in a single action. The precision finishing of gears by ECH is a productive, high-accuracy, long toollife gear finishing process. The present study contains a detailed description of the process principle, influencing parameters, process capabilities, equipment details, applications, advantages and limitations, and comprehensive literature review of past research work on the ECH of gears along with some guidelines for further research with an objective to revive the interest of the global research community to mature this process further.

Investigation into magnetorheological abrasive honing (MRAH)

A scheme to finish external curved surfaces, by imparting rotation while the abrasive-mixed magnetorheological fluid (or abrasive-mixed MR fluid) is pushed up and down, is presented in this paper. Since the relative motions resemble those present in conventional honing, the proposed method is named as ‘Magnetorheological Abrasive Honing’ (MRAH). This paper outlines the design and development of magnetorheological abrasive honing setup. A DC electromagnet with cylindrical pole faces is used and measurement for magnetic flux density is done. Experiments are conducted with aluminum and austenitic stainless steel workpieces to understand the effect of magnetic field. Effect of initial roughness, workpiece rotation and process duration on finishing was investigated with ground austenitic stainless steel workpieces. It is observed that the improvement in finish is better for rougher surface and higher rotation speed of workpiece and a reduction in roughness is consistent with process duration.

Research on System Design of Ultrasonic-Assisted Honing of Gears

Ultrasonic vibration can reduce honing forces efficiently. As the honing wheel can be washed by ultrasonic cavitations of cutting fluids, its jams are decreased and the higher honing efficiency has been obtained. Therefore, gear honing combined with ultrasonic machining honing is a method for gear finish machining with its wide application future. Ultrasonic-assisted honing of gears is firstly proposed, its machining devices are manufactured based upon the design parameters derived by four-terminal network principle. Experiments of gear honing show that the machining traces on the tooth flanks in ultrasonic and traditional honing are different. The ultrasonic honing can produce a better tooth surface roughness (Ra 0.45 μm) than one obtained conventional honing (Ra 0.72 μm).