我的毕设展示

here we go！ so my graduation project was about the titanium al carbon
nitrogen coatings by 。。

下一张

as we know ，Toyota had developed a Fuel Cell Vehicle (FCV) called
mirai in 2014. so what does feul cell mean？ A fuel cell is
an electrochemical cell that converts the chemical energy into
electricity through the reaction between  hydrogen and oxygen 。

so the Fuel cell is different from ordinary batteries because it
requires a continuous source of fuel gas to sustain the reaction,
whereas in a battery the chemicals must have to be stored in the
battery already。

feul cell vehecals have some advantages。 firstly，there is no oil
needed。it just relies on environment-friendly resources。 secondly，it
can reduce carbon emissions。 thirdly， it has Better Fuel
Efficiency。comparaing with those cars use solar enery of diesel engine
， the fcv has a higher Energy conversion efficiency around 40%～60%
whats more，fcv offers a silent operation for drivers。

In a word ， Fuel cell vehicles are beneficial

下一张

there are many kinds of feul cells。accoring to their different
electrolytes。one of them，the Proton Exchange Membrane Fuel Cell uses
polymer membrane to transfer proton 。 the red region is
Catalyst，usually we use platnum。the purple region stands for the gas
diffusion layer， where the oxy and hy come in and out 。 and the
outermost is bipolar plate， which is our focus today。

to maintain good battery performance，there are some criterions for bp.
Of course it should be a great e and thermal conductor, it should be
impermeable to gas to avoid gas leakage。 since the cell works in a
hot ，acid water envorionment ， the bp should have great Corrosion
resistance。and the last two points is out of economic reasons 。

下

t has t chemical stability to survive the fuel cell environ- ment.
good。。。。 resulting in the highest power output. However, it has
problems such as high cost, low mechanical strength . Hence, the
search is on for better alternative。

However, as BPs are exposed to an operating environment with a pH of
2–3 at temperatures of around 70 ◦ C, metal plates are prone to
corrosion or dissolution. The dissolved metal ions may poison the PEM
membrane and hence lower the 。。

下一

we turn our attention to

extended tool life Titanium nitride has been available widely since
the last decade as a coating for tool steels。

there is aC According to ， tribological behavevor，

下

the experiment conditions are listed in the table。we adopt the widely
used ss316L as our su。。and to improve the adhesion of the c and the
s，we use ti target to form a 。。。 and the tialc target is combined by
tial and graphite。so this target with n， we get the wanted coating。

下

next， we analysis coated samples。as we can see， from the ramen 。。，we
notice there is a。。。。in 2 3 4. you may wonder why the ac exsits。 the
reason might be that ， the Gibbs free energy of tic is lower than that
of tin， so with the N flow rate increase， the n atom replaces the c
atom。 so the squeezed out carbon becomes ac

下

After anysing the samples， we get them cut into pieces， w。。 saturated
calomel electrode

we adopt the 3。。。where the refernce 。。is 。。calomel。。，and the
operating envi tem。。is around 70 Degrees Celsius controled by a 。。。。
the sulfuric acid 。。。hydrofluoric acid Hydrogen to simulate
anode oxygen for cathode

there are 3 in。。 first，indicates the thermodynamic corrosion tendency
。the second is 。。。，with which we get the 。。。。density， the most imp and
direct factor to describe ones c。re and the last，。。。eis ，you may be
fimilar with it。

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first，we get 。。。 Theoritically 　,the higher..but ..so we just need to
focus on whether it gets stable or not. Once the line get stable and
smooth， that’s when we can do the follow-up operation。

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in atual situation ，the cathode will be applied with a minus 0.1
volt，at such voltage， sample no1 has a smaller c c den ，means the
better 。。。，but other sample are worse。 the anode has same result。

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Unfortuanelly, we got the data of sample no.1 and no.2 in a very
random arrangement so it had been rejected. but from the anode we can
see sample no.1 shows the greatest charge transfer resistance, and it
is the anode that faces the biggest challenge of fighting against
corrosion. so we can draw the conclusion that, comprehensively，….

Well, let’s check the graphitization of this coating.

下

comparing the intensity of sample 3 4, the signal representing ac
increase，and the Characteristic G band representing graphite gets
sharper。 So we confirm there is a 。。occured in this pin-on-disc
process。

下

we pick the sample no。3 to investigate the effect of 。。 on corrosion
ability。As we can see， both in anode and cathode ，the opc improves 。
下
also ， the 。。。makes the corr cu den decrease。

下

and the eis result shows the charge transfer resistance of sample no3
gets greatly improved after graphitization 。so obviously，。。that
。。。。。。。

so from what has been discussed，we draw the 。。。。first，the coated smaple no1 which is under 0.5 sccm nitrogen flow rate can improves teh。。。。
and the g of this coating can enhance the ，，，，however