Yu Haojun

11 Questions 23 Answers 0 Followers

Questions related from Yu Haojun

How to calculate partial pressure of Fe and Al in the system through their activity and activator?

To some expert who may interested I'm doing pack cementation aluminizing by using FeAl alloy of different composition. In order to predict the coating composition of the coating, I have to know...

04 April 2015 9,214 2 View

What are the health concerns about using NaF in high temperature?

I'm planning to use NaF as avtivitor in pack cementation aluminizing process in high temperature (above 900C). What are the health concerns about using NaF in high temperature?

04 April 2015 3,240 2 View

What's the difference between Ar and H2 atmosphere in aluminizing process like CVD or Pack cementation?

Usually in Pack cementation, Vapor phase or CVD aluminizing process, two kinds of atmospheres are used with donor alloy(e.g. NiAl, FeAl, CrAl) and activator (e.g. NH4Cl): 1. inertia atmosphere...

02 February 2015 8,872 5 View

Can anyone tell me how to reduce the hardness of the platinum layer which is made by eletroplating?

I'm using the Johson Matthey Q-5 salt bath for platinum plating. The bath contains 5g/L Q salt, temperature ia 92 Celsius and pH adjusts to 10.5 by sodium hydroxide. The hardness after...

01 January 2015 1,278 11 View

How do I make sure there are no bubbles in the water lute valve?

I want to use a water lute to balance the pressure in a CVD instrument, the pressure in the chamber is increasing from 1 Pa to more than 1 atm, because this instrument will leak higher than 1 atm,...

12 December 2014 360 4 View

What is POU device for CVD facility?

POU device is usual used in semiconductor industy for cleaning the gas before they enter the centralized exhaust system. Is there anybody know detail about it and explain it to me a little...

12 December 2014 558 0 View

What is the reaction temperature of HCl and FeAl alloy?

Dear all, I'm using pack cemetation method to apply aluminide coating on surface of the alloy with activator NH4Cl, but the pressure of the chamber is not very stable above 800C, so I want to know...

11 November 2014 805 3 View

What is fused salt plating?

What is the difference between fused salt plating and eletroplating, any advantage? Can anyone help me with introducing some books or papers about fused salt plating. I will be very appreciate to...

08 August 2014 5,523 0 View

Why NAl form during aluminizing process by using NH4Cl activitor?

Out pack aluminizng tech and NH4Cl has been use in this process. A layer of AlN form on the surface of the coating at about 1000C and seems to prevent the formation of NiAl.

08 August 2014 3,937 4 View

What's the differences between a phase vapor aluminizing process and pack cementation?

I read from papers that an industralized aluminizing process usually has three forms; chemical vapor deposition, pack cemitation and phase vapor aluminzing processes. The last two are very...

06 June 2014 1,150 3 View

Is there any easy way to get a cross section of the aluminum oxide scale after 10 hours oxidation by using FE-SEM?

I used to bend the coating or scratch the scale off the surface, but the result is not always good, so there must be another way.

03 March 2014 4,838 5 View