How to reduce the intersplat boundaries in thermal spraying
04-18-2012, 08:54 AM, (This post was last modified: 04-18-2012, 08:56 AM by hustzc.)
#1
How to reduce the intersplat boundaries in thermal spraying
Hi, dear all

It is always reported the intersplat boundaries have a negative effect on properties of thermally sprayed coating. I have a question on this issue that how can we reducing the intersplat boundary or amount ?


In one paper, it was said that the faster the powder feeding rate is, the lower of the intersplat boundries is, in HVOF process. I cannot understand why???

Any suggestion or comment on above-mentioned questions would be very appreciated.


zhang cheng
Reply
04-18-2012, 04:07 PM,
#2
RE: How to reduce the intersplat boundaries in thermal spraying
Hi zhang cheng

The way I see it, the boundaries between splatted particles are a fact of life in thermal spray coatings. While these boundaries tend to be the weak link as far as strength and ductility are concerned, they are an important aspect in thermal spray coatings.

The qualities (bonding) of these boundaries I think is the important issue not the amount. Changing the amount or surface area of these boundaries will be dependent on the particle size and the degree of splatting. So does using coarser powders (larger spray particles) and or reducing splat size produce better coatings? Well it depends on what properties your after, but for strength I would say it would be a negative one. The reverse of what your question implies.

Post heat treatment sintering/fusing operations may reduce and strengthen these boundaries.

Quote:In one paper, it was said that the faster the powder feeding rate is, the lower of the intersplat boundries is, in HVOF process. I cannot understand why???

Neither do I Rolleyes
Reply
04-19-2012, 01:16 AM,
#3
RE: How to reduce the intersplat boundaries in thermal spraying
Hi Gordon

Thanks for your reply. Your answer is somewhat similar to that of Prof. Pawlowski.
He also suggests to post-treatment.

Here, Must the post-treatment necessary for HVOF-sprayed coating ?
Reply
05-16-2012, 01:30 AM,
#4
RE: How to reduce the intersplat boundaries in thermal spraying
Hi zhang cheng


Quote:Here, Must the post-treatment necessary for HVOF-sprayed coating ?

Not sure I understand your question.

Post heat treatment in most cases is not necessary and in many cases a big advantage as the coating can be applied without heating effects to the substrate.

In a few cases post heat treatment can be beneficial to the coating, but this has to be done with consideration to how this effects the substrate as well.
Reply




Possibly Related Threads…
Thread Author Replies Views Last Post
  Request for solution to reduce porosity in HVOF Tungsten Carbide Coatings sreenuvundela 7 12,287 07-22-2020, 08:01 AM
Last Post: Simon Kim
  HVOF/HVAF Thermal Spraying connoramcguigan 0 2,514 11-13-2018, 05:13 PM
Last Post: connoramcguigan
  YSZ thermal Spraying by HVOF and Flame mgbaca1a 2 2,648 09-24-2018, 08:57 PM
Last Post: mgbaca1a
Question thermal spraying simulation software ??? vladutzu86 4 9,489 02-08-2015, 05:29 PM
Last Post: kyawkyaw
  Thermal Spraying of Silica Nadiir 2 4,968 11-29-2014, 10:58 AM
Last Post: Nadiir
  Arc Spray Reduce the pores Met.Eng. 6 6,524 09-29-2014, 07:41 PM
Last Post: loriol
  Reduce unmelted particles in Combustion Wire Spray Alberto Villalobos 8 8,388 05-19-2014, 07:21 PM
Last Post: KevinS
Sad how to reduce the contaminant when spray on Ti Bler 3 4,162 01-08-2013, 02:26 AM
Last Post: Bler
  Reduce Porosity in Ceramic Coatings rik 5 11,273 03-13-2012, 10:05 AM
Last Post: loriolo
  Thermal Spraying Plastics PPSABoyce 2 9,420 11-10-2011, 01:06 PM
Last Post: MichiganMan
Question How do reduce tensile strength of coating Metco 52C-NS? Christine 24 30,036 10-27-2011, 03:51 PM
Last Post: Gordon
  How to thermal-spraying with very large area hustzc 3 5,938 08-25-2011, 01:21 PM
Last Post: LEN WOOD
  learner on thermal spraying graham 4 8,014 12-29-2008, 04:29 PM
Last Post: graham
  Thermal spraying copper parts DVB 6 10,810 03-19-2008, 04:50 PM
Last Post: Gordon
  Thermal spraying coating develop William 6 9,527 03-17-2008, 06:03 AM
Last Post: William



Users browsing this thread: 1 Guest(s)





Surface Engineering Forum Sponsor - Alphatek Hyperformance Coatings Ltd