In the present study, laser cladding of Inconel 718/TiC metal matrix composite coating on SS 304 was carried out using a 2 kW Yb-Fiber laser by preplaced and blown powder method. The molten pool thermal history during the deposition process was monitored using an IR pyrometer and correlated with the evolution of microstructure. The effect of various process parameters, viz. laser power ‘P’ (400 W – 1200 W), scanning speed ‘V’ (200 mm/min to 1400 mm/min) and powder feeding rate (8 g/min – 20 g/min) on the molten pool lifetime and cooling rate is investigated. Molten pool lifetime increased and cooling rate decreased with the decrease of scanning speed and increase of laser power. However, scanning speed had dominant effect on the molten pool lifetime and cooling rate compared to laser power. Moderate molten pool lifetime resulted in the formation of shell-core structure between Inconel 718 matrix and TiC particles. The longer molten pool lifetime (>0.45 s) resulted in complete decomposition of TiC particles rendering brittleness to the coating. The feasibility of detecting TiC particle decomposition in Inconel 718 matrix from the recorded thermal cycles based on multiple solidification shelfs is discussed. At the end, a process map based on a combined process parameter, PD/V² (spot diameter D) and molten pool lifetime (τ) was developed. An optimum range of molten pool lifetime i.e. 0.25 s < τ ≤ 0.45 s was found to result in a good quality of coating with the formation of shell-core structure both in case of preplaced and blown powder laser cladding method.

在本研究中，使用2 kW Yb光纤激光器通过预先放置并吹塑的方法对SS 304上的Inconel 718 / TiC金属基复合涂层进行了激光熔覆。使用红外高温计监测沉积过程中的熔池热历史，并将其与微观结构的演变相关联。各种工艺参数的影响，即。激光功率“ P”（400 W – 1200 W），扫描速度“ V”（200 mm / min至1400 mm / min）和送粉速度（8 g / min – 20 g / min）对熔池的使用寿命和研究冷却速度。随着扫描速度的降低和激光功率的增加，熔池寿命增加，冷却速率降低。但是，与激光功率相比，扫描速度对熔池寿命和冷却速率具有主要影响。中等的熔池寿命导致在Inconel 718基体和TiC颗粒之间形成壳核结构。较长的熔池寿命（> 0.45 s）导致TiC颗粒完全分解，使涂层变脆。讨论了从记录的基于多个凝固层的热循环中检测Inconel 718基质中TiC颗粒分解的可行性。最后，基于组合的过程参数PD / V的过程图 讨论了从记录的基于多个凝固层的热循环中检测Inconel 718基质中TiC颗粒分解的可行性。最后，基于组合的过程参数PD / V的过程图 讨论了从记录的基于多个凝固层的热循环中检测Inconel 718基质中TiC颗粒分解的可行性。最后，基于组合的过程参数PD / V的过程图²（点直径D）和熔池寿命（τ）得以发展。发现熔池寿命的最佳范围（即0.25 s <τ≤0.45 s）可在采用预放置和吹塑粉末激光熔覆方法的情况下，形成具有壳核结构的涂层，从而获得良好的涂层质量。