Work Report of 3-4 weeks

Work Report
1.The work that I have done in the two weeks:
①Do the experiments of the AZ31B and new material AM602Ca
a.AZ31B samples
In order to find the FSW parameters of the thick plates, two plates were used together. Material: 200mm（length）×35 mm（width）×5mm（thickness）AZ31B
Tool: M6 t 4.8 shoulder 15 SKD61
Processing parameters(1 and 2 are on the same plates)﹕
In the four experiments, only the third one could make the two plates together. The groove like defects which were caused by insufficient heat input per unit length of the weld could be found on the surface of the FS weld in the four times experiments. Maybe the heat conduct speed the thicker magnesium alloy is higher than the SKD under plate.
The surfaces of the samples are shown in the Fig.1.
a b
Fig.1 (a) and (b) are the surfaces of the 1 and 2 processing parameters; (c) and (d) are the surfaces of the 3 processing parameter; (e) and (f) are the surfaces of 4 processing parameters.
②Do the FSW experiments on the new material(Mg-6%Al-0.5%Mn-2%Ca):
Material: 400mm （length ）×80 mm （width ）×14mm （thickness ） Tool: M6 t 4.8 shoulder 15 SKD61 Processing parameters
The surfaces of the samples are shown in the Fig.2.
c
e
f
d
Fig.2 (a) the surfaces of the 1 and 2 processing parameters; (b) the surface of 1 processing parameter; (c) the surface of 2 processing parameter. Question: Could I cut the samples to do the analysis?
③ cut and etching the samples of AZ31B
After polishing the welding zone could not be found directly and I should etch it first. Etching solution is very important in the etching step and there are many kinds of the solution for magnesium alloys in the papers, but they do not identify the etching solution for the macrostructure and microstructure . Some of them are shown below: a.5g picric acid ,5mL acetic acid, 20mL water,150mL ethanol; b. 5g picric acid ,5mL acetic acid, 2mL nitric acid, 100mL ethanol; c. 5g picric acid, 30 mL ethanol and add water to 100 mL ； d. 10g picric acid, 175 mL ethanol, 25mL acetic acid, 25mL water e. 1mL nitric acid, 75mL ethyleneglycol, 24 mL water
f. 4 mL nitric acid, 96mL ethanol/ 2 mL nitric acid, 98mL ethanol.
g. 2g oxalic acid, 100mL
The picric acid is used commonly in the magnesium alloy etching, but it could not be found and ordered in our lab, so I used the solution of 4 mL nitric acid, 96mL ethanol/ 2 mL nitric acid, 98mL ethanol. I still could not find the welding zone with the solution of
a
c
b
4 mL nitric acid, 96mL ethanol, and the welding zone could be seen but not clearly with the solution of 2 mL nitric acid, 96mL ethanol under long time etching.
④Observe the experiments of Mr. Ji and Mostafa.
2.The work that what I will done next two weeks.
Try to find the etching solution and go to complete the work of observing of the macrostructure and microstructure of the welded plates and the micro-hardness of the samples.。