Research Status of Subsequent Machining of Laser Cladding Layers

2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.

2020 ◽  
Vol 14 (1) ◽  
pp. 6461-6472
Author(s):  
Nitin Ambhore ◽  
Dinesh Kamble ◽  
Satish Chinchanikar

The machined surface quality and dimensional accuracy obtained during hard turning is prominently gets affected due to tool wear and cutting tool vibrations. With this view, the results of tool wear progression on surface quality and acceleration amplitude is presented while machining AISI 52100 hard steel. Central Composite Rotatable Design (CCRD) is employed to develop experimental plan. The results reported that vibration signals sensed in a tangential direction (Vz) are most sensitive and found higher than the vibrations in the feed direction (Vx) and depth of cut direction (Vy). The acceleration signals in all three directions are observed to increase with the advancement of tool wear and good surface finish is observed as tool wear progresses up-to 0.136mm. The vibration amplitude is discovered high in the range 3 kHz – 10 kHz within selected cutting parameter range (cutting speed 60-180mm/min, feed 0.1-0.5mm/rev, depth of cut 0.1-0.5mm). The investigation is extended for the development of multiple regression models with regression coefficients value 0.9. These models found statically significant and give dependable estimates between a tool vibrations and cutting parameters.


2013 ◽  
Vol 690-693 ◽  
pp. 2026-2029 ◽  
Author(s):  
Guo Jun Dong ◽  
Lai Zou ◽  
Ming Zhou

The demand for surface quality and dimensional accuracy of ferrous metallic components has increased markedly at present. Whereas, it is clear known that diamond tool could not be used for cutting operation of ferrous metals ascribed to excessive tool wear. In this paper, a series of experimental investigations for various stainless steels with ultrasonic vibration assisted turning were proposed. The micro-morphology of rake and flank face of diamond was detected by scanning electron microscopy, in order to discuss the influence law of material composition on tool wear. In addition, the effect of cutting parameters such as depth of cut, feed rate and amplitude on tool wear and surface quality were deeply studied with ultrasonic vibration cutting. The results revealed that this technological measure has enhanced tool life, decreased cutting force and improved surface quality to a large extent.


2011 ◽  
Vol 138-139 ◽  
pp. 732-736
Author(s):  
Ba Sheng Ouyang ◽  
Run Juan You

Cladding experiment with parameter variations was presented to manufacture the better processing property coating by laser cladding self-fused Ni-based ceramic powder of ZrO2 composite on the excircle surface of 304 SUS. The influence of the laser process parameters on macroscopic view, microstructure and micro-hardness of the laser cladding layers were investigated. The results show that we can get better coating when laser power is 1.5KW, and that the cladding layer microstructure has the trend of refined framework with the growing of scanning speed; micro-hardness will be higher and distribution from substratum to surface with little fluctuate by optimizing scanning speed.


Author(s):  
Mingsan Xu ◽  
Jibin Jiang ◽  
Bingbing Li ◽  
Weilong Cong ◽  
Dongdong Zhang

The purpose of this investigation is to test the laser cladding of different alloy powders onto 1045 medium-carbon steel substrates for parts remanufacturing. The types of alloy powder, laser output powers, and scanning speeds are selected as influencing factors to conduct laser cladding experiments with orthogonal design on the carbon steel 1045 substrate. Bonding shear strength and microhardness of the cladding layer and the substrate are tested and analyzed. The high resolution scanning electron microscopy and energy dispersive X-ray spectroscopy are also used to analyze cladding layers, microstructures, and elements. The experimental results show that a good metallurgical bond is formed between the cladding layer and the substrate without porous cracks and other defects. Shear stress intensity of nickel-based powder is two to three times higher than that of substrate material, while iron-based powder is five times higher than the substrate material. The type of the powder is the most significant factor and laser power is the least. The hardness of outer cladding layer is higher than that of bonding section and inner section. In the heat-affected zone, hardness is higher than that of the substrate material.


2013 ◽  
Vol 395-396 ◽  
pp. 1127-1131 ◽  
Author(s):  
Wei Zhang

The experiments of laser cladding on the surface of 20 steel were made. High-chromium (Cr) cast iron powder was used as cladding material. The microstructure and hardness of laser cladding layers under different scanning speed were studied. The experiments showed that high-Cr cast iron cladding layer had better properties such as minute crystals, high density, no crack, no gas cavity and good metallurgical bonding with base metal. When the scanning speed was low, such as 10mm/min, the microstructure of cladding layer was cellular dendrite. There were much carbide with the shape of fish-bone distributing among cellular grains. Under higher scanning speed (from 100mm/min to 300mm/min), needle-shaped primary cementite would come into being. When laser scanning speed was 500mm/min, the carbide of cladding zone was very thin. With the increasing of laser scanning speed, the average hardness of cladding zone increased from 388HV0.2 to 580 HV0.2.


Author(s):  
Shoujin Sun ◽  
Milan Brandt ◽  
Matthew S Dargusch

Geometric features of the segmented chip have been investigated along with the volume of material removed at a cutting speed at which tool wear is characterized by the gradual development of flank wear when cutting Ti-6Al-4V alloy. The chip geometric variables varied with an increase in the volume of material removed as the combined effect of change in tool’s geometry and increase in cutting temperature. Plastic deformation dimples were observed as periodical regions on the machined surface, a row on each undeformed surface and region on the top of the slipping surface of the segmented chip when cutting with new tool; these dimples on the undeformed surface and machined surface are elongated in the direction of chip flow. All these dimples became less with an increase in the volume of material removed and almost disappeared when the chip was removed with the worn tool at the end of its life. A model of segmented chip formation process has been proposed to satisfactorily explain the formation of the plastic deformation dimples on the undeformed surface and machined surface of the segmented chip produced with a new cutting tool and the transition of chip geometry with the evolution of tool wear.


2013 ◽  
Vol 764 ◽  
pp. 47-53 ◽  
Author(s):  
X.R. Zhao ◽  
Dun Wen Zuo ◽  
H. Cheng ◽  
Q.T. Li ◽  
S. Dai ◽  
...  

The Co-base alloy laser cladding layer was coated on the 2738 mold steel surface by using the TJ-HL-5000 transverse-flow CO2 continuous laser. The morphology and hardness were investigated by metallography microscope, scanning electron microscopy (SEM), X-ray diffraction (XRD) and microhardness tester. The metallography microscope and SEM investigations show that from interface to surface along the cross section direction, the cladding layers consist of plane crystal layer, columnar crystal layer, dendrites layer and surface cellular crystal layer, respectively. XRD results indicate that the cladding layer is made of γ-Co, Cr23C6, MoC, FeCr and Co3Mo2Si phases. The micro-hardness of the laser cladding coating was about 900-1100HV1, 3 times or more of the steel substrate. And the mechanisms of microstructure formation and strengthening are investigated.


2010 ◽  
Vol 37-38 ◽  
pp. 1384-1387
Author(s):  
Neng Wen Liu ◽  
Yun Shan Wang

Copper has some excellent performances in anti-erosion and high thermal conductivity. It is applicable in many important fields. In the paper, two methods of preparing Ni-Cr alloy cladding layer on the surface of copper are proposed, including the spray welding and YAG pulse laser cladding .Then the Ni-Cr alloy layer prepared on the copper is investigated by optical microscopy, there is no hole and crack in the cladding layer. The experimental results show the coating is metallurgically bonded with the substrate. In comparison to the prepared cladding layers, the Ni-Cr cladding layer prepared by YAG pulse laser is the better, the size of copper is not restricted, and the copper substrate isn’t preheated.


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