Hi,
Thanks for using Syncfusion Products,
We have analyzed your sample and we like to inform you that there is a property called "DisposeOnUnload" in Chart which has to be set to true in order to clear the memory leak. We have modified the sample as per your requirement and it can be downloaded from the link below.
If you still face the problem can you please open a Direct Track incident along with the version details of the Chart so that we can provide patch accordingly.
Please let us know if you need further clarifications.
Thanks,
Michael Prabhu.