You may try following methods to open corrupt .docx file.
MS Word's in-built method Open and Reapir- File menu > Open > Select file > click down arrow beside the open button > Open and Repair.
Open with Open Office- Try to open MS Word document in Open Office.
Third Party tool- Stellar Phoenix Word Repair Tool which is a user-friendly and competent tool to repair corrupt Word DOC/DOCX Files without making any change in original images, text, headers and footers, fonts, and hyperlinks.
Open below link and download the demo version of the software.
go through:
http://www.mannatsoftware.com/stellar-phoenix-word-repair.html