Papers by Keyword: Belt Grinding

Abstract: Belt grinding is characterized by elastic contact grinding. Generally, the non-uniform material in complex machining area could be removed by repeated grinding or longer dwell-time grinding to obtain the required grinding capacity, which leads to low efficiency, difficult dimension accuracy control and poor surface quality. It should be considered thoroughly surface geometry, grinding force and system stiffness in surface belt grinding. Belt grinding parameters can be then dynamically adjusted. This paper focuses on controlling material removal efficiently and uniformly in marine propeller belt grinding. The material removal process is modelled considering elastic contact between grinding wheel and workpiece. Then, a grinding depth and grinding dwell time control strategy of surface belt grinding is proposed based on rigid-flexible coupled analysis. The variable feed grinding experiments were carried out on the developed five-axis CNC belt grinding machine integrated measuring and machining. The marine propeller with cast aluminum bronze (ZCuAl₈Mn₁₃Fe₃Ni₂) was employed to validate the proposed controllable material removal strategy. It is shown that the proposed strategy is feasible and efficient.

Abstract: The majority of aero-engine components are designed and manufactured with nickel-based superalloy GH4169 in mind. There is little information available in the literature related to belt grinding processes of aero-engine components. Up to now, limited research has been reported in the use of belt for grinding aero-engine components made of nickel-based superalloy GH4169. A case study of an abrasive belt grinding performance applied on nickel-based superalloy GH4169 in manufacturing processes is presented, aiming to investigate the possibility of using belt grinding as a operation for components made of nickel-based superalloy GH4169. For the ‘optimised’ grinding conditions, the belt service life is evaluated by changing grinding parameters (grinding speed, contact force and oscillation frequency), and the following output measures are obtained: material removal, belt wear and grinding ratio. As a result, the maximum grinding ratio of G is 8.8, it could be concluded that belt grinding might be considered as a viable process for grinding aero-engine components.

Abstract: The use of GH4169 nickel-based superalloy for the manufacture of gas turbine engines components for aerospace/energy applications has become a routine exercise. However, components with complex designs specifications might pose manufacturing challenges especially when grinding processes are needed to enable their compliance with tight industrial standards for workpiece surface integrity. Information on grinding processes for such sensitive industrial applications is scarce. The paper reports on the influence of grinding methods/strategies on the quality and integrity of workpiece surfaces obtained after abrasive belt grinding methods on GH4169 nickel-based superalloy. The influences of grinding speed, contact pressure and oscillation frequency on surface roughness were discussed. The performance of the abrasive belt and surface topography were discussed. As a result, the maximum surface roughness of Ra is 0.072μm, and have a good performance of the abrasive belt, it could be concluded that abrasive belt grinding might be considered as a viable process for grinding aero-engine components.

Abstract: In gas turbines and turbo jet engines, high performance materials such as nickel-based alloys are widely used for blades and vanes. In the case of repair, finishing of complex turbine blades made of high performance materials is carried out predominantly manually. The repair process is therefore quite time consuming. And the costs of presently available repair strategies, especially for integrated parts, are high, due to the individual process planning and great amount of manually performed work steps. Moreover, there are severe risks of partial damage during manually conducted repair. All that leads to the fact that economy of scale effects remain widely unused for repair tasks, although the piece number of components to be repaired is increasing significantly. In the future, a persistent automation of the repair process chain should be achieved by developing adaptive robot assisted finishing strategies. The goal of this research is to use the automation potential for repair tasks by developing a technology that enables industrial robots to re-contour turbine blades via force controlled belt grinding.

Abstract: Titanium alloys have been applied to aerospacemedical and other fields. The surface roughness of titanium alloy about these areas is very high. Based on the results of orthogonal test, belt grinding surface roughness prediction model of TC4 Titanium alloy is established using linear regression method. The significant tests of regression equation are conducted and proved that the prediction model has a significant. The results indicate that the model has reliability on the prediction of surface roughness, abrasive belt grinding pressure has certain influence on the surface roughness, and grain size of belt and the belt linear speed have high significant influence on surface roughness and the influence coefficient are-0.9378 and-0.2317. While the contact wheel hardness and workpiece axial feeding speed have no significant influence on surface roughness.

Abstract: This paper deals with an investigation of surface integrity of Ti6Al4V alloy with zirconia alumina and SiC belts. The experiments were conducted under dry grinding environments in milling machine XS5040 equipped with belt grinding device. Microcosmic geometry parameters were measured with TALYSURF5 instrument, the surface morphology machined workpiece and the phase structure was analyzed using 3D viewer microscope, surface hardness for ground surface was measured by HXS-1000A instrument. The results show that surface quality maintain better level during a long period, the grinding affected zone was small(≤15μm), zirconia alumina belt has excellent performance than SiC belt during dry grinding Ti6Al4V alloy.

Abstract: Blades are the key parts of the turbine, which usually use materials such as 1Cr13 stainless steel. These materials are of high strength, great toughness, and good thermo hardening, but the process is difficult. Abrasive belt grinding has good grinding performance. Grinding tests of three kinds of abrasive belts were carried out on 1Cr13 stainless steel; the relationship between the material removal rate and the species, such as abrasive belt type, belt speed, the normal grinding force, and grinding fluid, was studied; after the belt grinding, the microscopic morphology of the surface was analyzed by SEM, and it revealed that the differences of the micro structure and basic wear law of different abrasives. The results show that in the process of abrasive belt grinding, the ceramic abrasive belt has the highest material removal rate. The material removal rate of alumina and zirconium corundum abrasive belt reached the maximum when Vs is about 25m/s or so, and ceramic abrasive belt is stable to maintain high material removal rate when Vs is at the speed range of 28 to 32m/s. The material removal rate can be improved several times when using grinding fluid of butter.

Abstract: Surface roughness is one of the most important parameters in grinding, which directly affects the quality of the processed surface and has quite a lot of effect on the shape and position accuracy, installation accuracy of the workpiece. In the grinding process, the surface roughness is formatted from the abrasive which effects on the surface of spherical head, and is the result of mutual interference between abrasive and spherical head. Many factors affect the surface roughness, such as the shape and size of contact roller, abrasive morphology, grinding method, the stiffness of machine tool and workpiece, abrasive wear and vibration in the machining process. All of these have an impact grinding surface roughness. In this paper, analyzed the belt speed, workpiece speed, abrasive size, workpiece diameter, sand-planting density on the surface roughness of spherical head in experimental. And the effect trend of factors on surface roughness of workpiece was analyzed. Some valuable information was provided for selecting suitable parameter in spherical head grinding.

Abstract: High-efficiency abrasive machining is one of the important technology of advanced manufacture. Combined with raw and finishing machining, it can attain high removal rate like turning, milling and planning. The difficult-to-grinding materials can also be ground by means of this method with high performance. In the present paper, development status and latest progresses on high efficiency abrasive machining technologies relate to high speed and super-high speed grinding, high efficiency deep-cut grinding, hard and brittle materials high-efficiency grinding, powerful grinding and belt grinding were summarized. The efficiency and parameters range of these abrasive machining processes were compared. The key technologies of high efficiency abrasive machining, including grinding wheel, spindle and bearing, grinder, coolant supplying, installation and orientation of wheel and workpiece and safety defended, as well as intelligent monitor and NC grinding were investigated.

Abstract: Marine propeller blade is composite of the free form surface, its machining method has been a difficult thing. The blade is processed by 4-axis belt grinding machine in this experiment, this paper analyze that the wear of the abrasive belt and the processing precision and the material removal rate of the blade according to the grinding performance of the blade material, the structural features of the vane, and the theory of 4-aixs belt grinding machine. Draw formulas with time for the belt wear height and the actual grinding depth. The life expectancy of the ceramic abrasive belt is the longest, and its the material removal rate is maximum in Three kinds of belt，and when the belt line speed is 30m/s or so, the material removal rate is maximum.