Parametrical optimization of laser surface alloyed NiTi shape memory alloy with Co and Nb by the Taguchi method

Abstract

Different high-purity metal powders were successfully alloyed on to a nickel titanium (NiTi) shape memory alloy (SMA) with a 3 kW carbon dioxide (CO 2 ) laser system. In order to produce an alloyed layer with complete penetration and acceptable composition profile, the Taguchi approach was used as a statistical technique for optimizing selected laser processing parameters. A systematic study of laser power, scanning velocity, and pre-paste powder thickness was conducted. The signal-to-noise ratios (S/N) for each control factor were calculated in order to assess the deviation from the average response. Analysis of variance (ANOVA) was carried out to understand the significance of process variables affecting the process effects. The Taguchi method was able to determine the laser process parameters for the laser surface alloying technique with high statistical accuracy and yield a laser surface alloying technique capable of achieving a desirable dilution ratio. Energy dispersive spectrometry consistently showed that the per cent by weight of Ni was reduced by 45 per cent as compared with untreated NiTi SMA when the Taguchi-determined laser processing parameters were employed, thus verifying the laser's processing parameters as optimum.

Study on mechanical performance of laser-welded NiTinol sheet

“…Between all other sources of energy, laser is the typically favored for many engineering applications (such as surface treatment, 14 joining, [15][16][17][18][19][20] etc.) because of the superior properties of the system: high processing speed, capability to attain reasonable control of heat input, minimum residual stress, good weld-bead profile and narrow width of heat-affected zone (HAZ).…”

Selection of Process Parameters for Optimizing the Weld Strength in Laser Transmission Welding of Acrylics

“…Cao et al [19] used the Taguchi experimental method to optimize different process parameters and to identify the dominating factors for laser cladding of ZE41A-T5 magnesium alloy castings. Ng et al [20] used the Taguchi approach as a statistical technique for optimizing selected laser processing parameters in laser surface alloying of NiTi shape memory alloy with Co and Nb.…”