An empirical-statistical model for laser cladding of WC-12Co powder on AISI 321 stainless steel

AISI 321不锈钢表面激光熔覆WC-12Co粉体的经验统计模型

Optics & Laser Technology, Volume 97, 1 December 2017, Pages 180-186

Mohammad Erfanmanesh, Hassan Abdollah-Pour, Hamidreza Mohammadian-Semnani, Reza Shoja-Razavi

Abstract:In this study, laser cladding of WC-12Co powder on AISI 321 steel substrate was optimized using an empirical-statistical viewpoint. The correlations that exist between key parameters of the process (i.e., laser power, scanning speed, powder feeding rate) and geometrical characteristics for single clads (i.e. height, width, dilution, and wetting angle) were predicted and analyzed by regression method (RA). The preliminary geometrical considerations allowed to choose the processing parameters which led to high quality clads with minimum porosity. All considerations finally resulted in the development of a processing map that shows the optimum parameters for laser cladding process of WC-12Co powder on AISI 321 stainless steel.

Microstructure and properties of Ti/TiBCN coating on 7075 aluminum alloy by laser cladding

7075铝合金表面激光熔覆Ti/TiBCN涂层的微结构和特性

Surface and Coatings Technology, Volume 334, 25 January 2018, Pages 142-149

Yuxin Li, Pengfei Zhang, Peikang Bai, Liyun Wu, Zhanyong Zhao

Abstract:Ti/TiBCN coatings were fabricated on the 7075 aluminum alloy by laser cladding. The influence of TiBCN content on microstructure, micro-hardness, electrochemical corrosion and wear resistance of the cladding coatings were studied by SEM, XRD, Vickers micro-hardness tester, a typical three-electrode electrochemical workstation and straight-line-reciprocating dry sliding wear tester, respectively. The results showed that, when TiBCN content was 15 wt%, the microstructure of coating zone mainly composed of equiaxed grains and white lath-like crystals and that of transition zone mainly consisted of the elongated dendrite crystals and white small particles. Furthermore, the average hardness of the Ti/TiBCN cladding coating is 750HV0.2, which was about 5 times higher than that of the substrate (~ 127HV0.2), and the corrosion potential (Ecorr) reached − 1.271 V and the corrosion current density (Icorr) was 3.155e− 005 A/cm2, which was one magnitude low than that of the substrate (2.269e− 004 A/cm2). The narrow and shallow plowing grooves uniformly distributed on the worn surface and have less wear damage and the mass loss of the cladding coating was only 2.4 mg in 20 min.

Effect of alloy elements added on microstructure and hardening of Al/SiC laser clad coatings

合金元素对Al/SiC激光熔覆涂层微结构和硬化的影响

Journal of Alloys and Compounds, Volume 727, 15 December 2017, Pages 671-682

Ainhoa Riquelme, María Dolores Escalera-Rodríguez, Pilar Rodrigo, Enrique Otero, Joaquín Rams

Abstract:Al/SiCp coatings were deposited on AA6082 aluminum alloy using a laser cladding process. The SiC particles tend to dissolve and react with aluminum to form detrimental Al4C3 and a strategy has been developed to avoid this problem. The method employed consists of the addition of different alloying elements (Si or Ti) to the composite matrix powder to modify the equilibrium of the Al4C3 formation reaction. Different percentages of Si were tested and the formation of Al4C3 was totally inhibited when the percentage of silicon was higher than 40 wt.%. The addition of Ti particles to the composite matrix also inhibited the formation of Al4C3. The coatings microstructures were analyzed by optical microscopy and scanning electron microscopy. The effect of the laser control parameters on the coating geometry, coating-substrate interface and adhesion has been analyzed. The coatings mechanical properties were measured using microhardness and nanoindentation techniques.

Microstructure and high-temperature wear mechanism of laser cladded CoCrBFeNiSi high-entropy alloy amorphous coating

激光熔覆CoCrBFeNiSi高熵合金非晶涂层的微结构和高温磨损机理

Materials Letters, Volume 211, 15 January 2018, Pages 235-238

F.Y. Shu, L. Wu, H.Y. Zhao, S.H. Sui, B.S. Xu

Abstract:Amorphous coating was successfully fabricated on low carbon steel substrates with one-step laser cladding method using CoCrNiSiBFe high-entropy alloy powder. The microstructure and high-temperature wear mechanism of the fabricated coating was investigated. The coating exhibited layered microstructure including the columnar dendrites as the bottom layer and the amorphous-matrix layer with β-Co phase as the minor phase. The content of amorphous phase in the upper surface was up to 85.1%. Different high temperature wear mechanism was exhibited by the two layers leading to a remarkable decrease of wear mass loss and thus a much better wear resistance in the amorphous layer.

Effect of rare-earth on friction and wear properties of laser cladding Ni-based coatings on 6063Al

稀土元素对6063Al表面激光熔覆Ni基涂层摩擦和磨损性能的影响

Journal of Alloys and Compounds, Volume 727, 15 December 2017, Pages 278-285

Chenglei Wang, Yuan Gao, Zhichao Zeng, Yaokun Fu

Abstract:The Ni60 alloy cladding layers added with La2O3, Y2O3, CeO2 were prepared on the surface of 6063Al using laser cladding technology. The effects of rare-earth oxides on the microstructure, hardness, friction and wear properties of laser cladding Ni-based coating were investigated by XRD, SEM, microhardness tester, friction and wear tester. The results showed that, the main phase composition of the cladding layers is β-NiAl (Cr), Al3Ni, AlNi3 and Al, and the Ni60 cladding layers added rare-earth oxides will produce chemical reaction that involved in the cladding process to form stable rare-earth compounds. Compared with Ni60 cladding layer without rare-earth, the micro-morphology of the Ni60 cladding layers added with La2O3, Y2O3 and CeO2 respectively are preferable, which are more smooth and without obvious pores and cracks. The dendritic structures of Ni60 cladding layers are coarse, and there are many grain segregation in the local area, accompanied by a large number of pores, while the organization of Ni60 cladding layers added with rare-earth oxides are compact dendrite, and the grain are obviously refined. The hardness of the cladding layers from the surface to the substrate is gradually decreased with increasing depth of the cladding layer. Compared with Ni60 cladding layer without rare-earth, the wear properties of Ni60 cladding layers added with rare-earth La2O3, Y2O3 and CeO2 respectively are improved.